Of course being SM they have access to some nice tech. They could just be carrying a teleport beacon.

Oh-HO! Touche sir!

Excellent idea! Now, lets just tempt the acolytes into activating the beacon and teleport them up aboard the inquisitorial marines battlebarge :-) No, seriously it's a great plan. It is not uncommon for droppods to have an advanced integrated locator beacons, including a teleport homer among many other things. These are normally used to coordinate reinforcements, but could definitely work to target and retrieve a squad. Of course the squad could arrive by teleport as well (appearing beside the improvised altar maybe?), but considering the risks involved with teleporting and the drama of the scene I'd still reccomend the pod.

A completely different thought.You should put some firm voice into explaining to your players that the astartes pattern boltguns are not useable wihtout the neural network connections that is built into a spacemarines body and armor. Their amunition is not compatible with "civilian" boltguns either. Similar goes for powefists, lightning claws and indeed the power armors! Because I don't think you want your players to have quite such a big inflation of gear. They might be allowed to pick up some grenades, unless you want them too to be primed and armed by connection to the neural network.

Now that I think of it. It would be quite doable for the marine commander to retrieve his downed squad by means of the telepor homer. Thus leaving nothing more than a heap of dead Tau, wounded acolytes and an empty droppod behind. Retrieveing the droppod by teleporter is not worth the effort, but the marines geneseed is very valuable indeed.

Mellon said:

According to Imperial Armour III, that's actually the case - there are dataports on the grip of an Astartes bolter which link into the wielder's gauntlets, transferring information from the gun (ammo remaining, weapon temperature, images from the pict-sensor in the bolter's iron sights) to the warrior's Autosenses while it sends genetic information to the gun to unlock the gene-coding and allow the weapon to be fired.

Considering the fact that even some real-life modern police forces (like South African police) are equipping their hardware with fingerprint sensors to prevent the guns from ending up in criminal hands I'd assume quite many imperial organizations routinely make use of biological ID (retina scans, fingerprints, voiceprints and/or DNA scans) to make their weapons "unlootable". Last thing a devoid Arbiter wants is a dirty mutant scum capturing their weapons to be used against Imperium.

A couple demo charges thrown through a window should do the trick well enough, even if a) you didnt use the lolwhat rules for explosives from IH b) the task was only to kill the bride/groom. Or, hell, a civilian-pattern Spacecraft with enough hidden cannon and ammo for a one-shot Orbital bombardment. But it seems your intent here is to mess up/put the fright on your Acolytes, then have your Inquisitor save the day, yes?

A squad of DW Marines is just as much overkill as a Temple Assassin tbh; imagine a squad of sub-Eversor-level killers decked out in military power armour, advancing from multiple directions under a constant stream of Metal Storm rounds - each round of which is basically a shot or two from a suped-up MeatHammer at point-blank. I don't care what your interpretation of Space Marines is, psychic powers relating to mind-cooking (your best option, I'll grant) usually need LoS, and I don't see anything less than a Farseer getting LoS without being mashed/pulped.

However, if your heart is set on this kind of bacon-saving mission, and involving DeathWatch no less, I would advise something a little different.

1) The Marines will not die. The last thing you want to do, Heretical or not, Inquisitor or not, is piss off a Space Marine Chapter . Let alone a half-dozen.

2) A good idea, stated above, reasons that the bodies will be retrieved, thus removing any temptation to try and use SM equipment. i would go one step further and say that this is how the Marines are extracted, before they are all taken down (not even killed, as above).

3) Ways to not die; You seem to be angling for the Marines to be under false impressions for this mission, so run with that idea. Have the marines - perhaps not even arrive by pod, but emerge from hidden locations arround the chapel - announce themselves, and demand that someone else hands themselves over from immediate and less painful justice, as others have suggested. Make it some other Inquisitor, to clue the wedding party in, but have it be some commonly-agreed-upon radical Inquisitor that is rumoured to be in the sector. Perhaps this redical is not even a psyker, so that when the DW start dropping by such means they begin to suspect foul play or at least faulty information, retreating by means of personal teleport homers.

^ That's my rambling on the subject, here's my ideas on a possible event break-down;

- The Acolyte cell turns up at the wedding early, seed rumours of the obviously-Radical Inquisitor (not thier soon-to-be enemy, there's bound to be more than one floating around) and the civilian-pattern Imperial Ship in low orbit.

- Ceremony commences, or gets interrupted beforehand if you wish. (Of course, as a tried-and-tested solution, have the next point happen immediately after "..or forever hold your[/to the Emperor's] peace." )

- Seriously low-grade carpetbombing of the general area, from hidden cannons upon the Imperial Craft (meant more as an introduction/interruption and to clear the streets of non-essentials). The chapel shakes, air-bursting fragmentation lacerates those on the streets outside, etc

- The DW marines, having infiltrated-and-concealed/pin-point-teleported into positions surrounding the Chapel, emerge. The earth shakes less severely as they advance, screams of terror from 'Imperial' citizens outside witnessing thier immenant doom.

- Announciation of Imperial interests, demands for Radical Inquisitor X to check-in and subsequently not check-out. Acolytes get to be terrified AND confused, not knowing who the *** is wrecking such mis-guided disstruction, while thier Inquisitor will probably recognize Marine vox (hell, no I remember what your cell has apparently done, they might recognize it as well) and possibly recognize/suspect the machination of his rival.

- The cell can try and reason with the Marines/convince them of thier true identities, but after a few moments with no-one coming out to be smote, they shall state thier intent to come get you, opening fire with MetalStorm ammunition from mulitple angles as they advance.

- Have a few NPC members of the party try a few methods of attack that you think to be futile, so that your players can watch them die messily.

- Then have your party have to work togethor with thier Inquisitor, cause various distractions/attacks so that he/she is open to mind-slap one marine at a time. Maybe some technical-minded PC can hack into the DW vox channel so they have a better idea of whats going on (although going by your interpretation this will either be impossible or futile, as they will speak a battle-language designed solely for this mission).

- Anyway, in the face of having 2/3-1/2 of thier force nocked-out/partially maimed as well as vastly superior psychic powers over what was expected, the marines shall be teleported out by personal beacon, back to the Imperial Craft.

- Another general, low-key bombardment from the craft, following which it shall burn thrusters untill it can enter the Warp and retreat. Possibly the combination of 'low-orbit' and 'burn thrusters' will wipe out a couple scattered settlement closer to the craft.

And then your Acolytes will be sent straight out for clues/a mission to hunt down Rival Radical Inquisitor Y, upon final Big Bad confrontation with they might recieve from said DW marines, angry at previous mis-use.

Blurgh, went on to long.

Good thoughts, a couple things though, 1st is that I am not afraid to have them burn fate points, in fact, I rather want them too. One of them has managed to save up an astounding four, and another has earned an extra unfairly. Oh for the love of the God-Emperor do I want the Death Watch to ***k them up. 2nd, the Death Watch are being sent by an Inquisitor Lord on a power trip who views our inquisitor as someone in his way, which in his eyes, is paramount to arch-heresy. Largely, I think I'm going to have to wing it with this battle. I have enough in mind to make it go in the direction I want. Luckily, for the players there will actually be a second inquisitor present at the wedding (a pyromancer) along with his retinue (a cleric, a psyker, and twin battle sisters) all undercover and equally surprised of course, as well as some new friends from the Tau underworld. As far pissing off the Death Watch by killing some of their own, not so much an issue when the guy at the head of the crusade labels you an arch-heretic. The only ones who know better are actually the four other inquisitors of the crusade that aren't dead, hertical, or on a power trip. Which will lead to the players sneaking around, using the steadily worsening crusade as a cover as they attempt to stage a coup.

Milova said:

Bah! 4 fate points? That's nothing!

At the height of his career, my Techpriest had a whooping 7 fate points.

Then again, he was a smart bastard who knew how to stay out of harms way and never did anything reckless. And during the odd chances when he did get in harms way he tended to have enough armour and firepower to deal with it. Mechanicus Secutor for teh win!

Milova said:

Putting aside my feelings on how fast this "Lord" Inquisitor would come under fire (for failing to Crusade well, let alone his stupidity elsewhere) and the fact that 4 > 1 even in the Inquisition; Do you want your characters to survive at all?

Ganted, your plan for them is the only even semi-plausible way for them to survive, but belief might get stretched a bit...

Now, as far as pissing off a half-dozen Space Marine Chapters not being an issue when you've been officialy declared an enemy of the Imperium... Do you see the flaw there? It's like your Party Inquisitor plays right into the hands of his enemy; Not only playing hardball against one of the scarcest resources the Imperium has when they're clearly misinformed, but... Ok, let me try and put it into RL terms.

Let's say that, one day, out of the blue, a couple dozen guys from each of the SAS, Mossad, SEALS, Green Berets, etc were found brutally tortured, mutilated and then messily killed. Then have the person/group responsible have thier identity and person-non-grata status announced by the Head of State from every nation in the world , the UN and religion heads declare them to no longer be considered Human, and to top if off they've got an honest-to-Gods plan to destroy the world and the means to enact it.

Basicaly, thier Inquisitor, at least, should have the intelligence to realize that pissing off that many badasses is a bad idea. Or your entire group is well and truly f*cked . But then, this may come from my take on SM in DH; forces of nature more than adversaries. Try to go right up against them, and no matter how good you may think you're doing at the time, you're only making it worse for yourself.

First, I'll admit I misread your post the first time, I thought you were saying that pissing of a half dozen space marines would be terribly bad (under normal circumstances I'd whole heartedly agree) as opposed to their chapters at large. True, the prospect of being hated by the chapters is an issue, but the main fact that the group is ALREADY labeled heretics, and of the level that they need a Death Watch killsquad just for them, is enough for any imperial force to be ready to slaughter them. This also goes for your analogy as well. The heads-of-state and religious heads would have already declared this on them, and THEN sent the team of special forces. The damage is done already. They are being hunted. It's the over-the-top unexpected twist. "Hey, you guys are now the enemies of the Imperium". Players: "Oh s***."

Also, the four Inquisitors to one trumping the highest ranked one, I agree, especially when two of them are also High Inquisitors. This is why a coup will take place. The problem is that in the meantime, Inquisitor-Commandant Novalus, has the entire crusade directly under his command with the signed support of the Inquisitor Sector (someone who is being rather misinformed about the status of things), and though the other inquisitors are unhappy with the situation they have yet to see his treachery. At this point he's just more of an a-hole chairman of the board, so to say.

Also, with how many conflicts all the chapters go through, I wonder at the impression that the deaths of any brothers would bring the wrath of the entire chapter down on the enemy. Maybe a planet, or a significant force that they can actually strike against, but a lone heretic that is already in hiding and being hunted by the inquisition? I'd think that the space marine commanders are more practical than a horde of barbarians. They maybe fanatical super soldiers, but they are soldiers. They're not unthinking. I would think that brothers lost during duty to the Death Watch might warrant at most, an offer of minor aid to the crusade forces (in which they'd have bigger fish to fry with a war about) rather than a chapterwide vendetta against several individuals. I just don't buy it.

Also, as to the physical abilities of space marines in DH. I am aware that the Death Watch are carrying high end gear given their association with the inquisition, but space marines can be killed by ordinary humans. Just look at Guant's Ghosts, or Caiphas Cain. Guant's kill team took out a squad of Chaos Marines in one-on-one or at most one-on-two combat. Cain took down a few himself. Something I've noticed in these forums in regards to space marines is that people tend to underestimate the space marines mind, and overestimate their bodies.

(Not as a statement to you, but one against these preconceptions:) Space Marines are not mindless tanks on crack that kill, kill, kill, till dey can' kill no more. They are not Necrons with Ork personalities that just manage to scream "For the Emperor!". They are the greatest of human soldiers, albiet fanatical, but anything but mindless or unstoppable.

Sorry for that little rant. I've just gotten fed up with some of opinions I've heard spouted about space marines for the past couple years. On a calmer note. Thank you for your feedback. I understand that the situation is unusual, and yes, using scum, or death cults, or even just storm troopers would be both easier and more plausable, but in my opinion not nearly as frightening, fun, or fulfilling when the players survive. 40k thrives on the over the top. That's why Mkoll was able to out stealth himself a Mandrake in Sabbat Martyr, and why Cain was able to single handedly take down a Genestealer Patriarch, oh and while I'm on it, Uriel Ventris was able to slay a Norn Queen.

Just keep in mind that Dan Abnett sometimes takes... liberties with the fluff. Yes, Space Marines are kill able. But sometimes he takes the view that they are quite easy to kill if the troops are competent enough. While based on the 40k Tabletop game this is true, Dark Heresy takes a different tack on the matter. Have you read Purge the Unclean ? Shades of Twilight in there has the statline for a Deathwatch Sergent and he's no pushover.

And since I am a big fan of Cain I will admit that he kills some though they are quite beaten up when they are encountered.

What I'm trying to say here is that although they are killable, something is very wrong if they can be defeated "one-on-one or at most two-on-one combat" unless their opponent is very special. While we're talking Abnett, I think Eisenhorn's encounter with that Chaos Space Marine near the end of Xenos demonstrates what I'm talking about. Our man Eisenhorn is totally outclassed but still manages to win through good old guile. Space Marines are armed with some of the best weapons and armor the Imperium can provide to say nothing of their augmentations. Exceptional examples from the fluff don't change that central idea.

numb3rc said:

True, I concede the point that those are exceptional situations, and that space marines are no push overs, anything but. I'm fully aware of how powerful they are. I do not take their presence lightly. Had I not had the intentions of using them to strip some fate points from my players, surviving the battle would earn them one. The fact that I'm using space marines to put the fear of the Emperor back into the players is just more exciting and fulfilling in the end. I fully believe that two inquisitors and their retinues, could survive such a battle. Just because they survive does not mean I'm taking things easy. These players are competent, and as I've said before have taken down a rogue space wolf before. What I didn't mention is that there was also a lictor and a warrior strain attacking as well. They not only killed all three, but got out of the warzone (albiet one was permanently taken out of play). I've always viewed the players as the main characters to their own fluff. Afterall, isn't that the point, to be the main characters to a grand story? The cases I mentioned above were exceptional in 40k, but in my opinion the players are supposed to live out the same exceptional situations. That's what fate points are for, to set the players apart from everyone else in the imperium. They are blessed by the Emperor. That what makes them able to survive such dire situations. (Luckily they are lucky enough to have 2, 3, or 4...which I shall remedy in the near future...)

Keep in mind the main thing that really makes the one stated Deathwatch SM horrible is that he is wearing artifacer power armor. That and his unatural toughness. Without the armor the SM isn't worse than the average Ork. (Fear the Ork in mega armor...) With good pen weapon it would be a hard fight, but quite doable.

The thing that irritates me about your analogy is that it uses Abnett. Varnias at least knows that I hate him, though apparently he's improved when talking about Imperial SM, at least. The thing with Gaunts Ghosts is that Abnett had the Marines as his "monster of the week"; brainless, down-right too-stupid-to-live, and apparently lacking a lot of thier standard gear/implants. Which is exactly what you were just complaining about, so having him as your champion confuses me.

Case in point, destroying a squad of Chaos Marines when the CSM are the ambushers. Come on, they had the drop on the Ghosts. And say what you want, but Chaos doesn't make you stupid, not even Khorne. Just because they're portrayed that way doesn't mean it would be at all accurate, especially taking into account all the fluff. Some of these guys rode round with Horus, then spent a couple centuries partying on the daemonworlds in the Eye of Terror. Survival of the fittest, people. This is a fight where Gaunt (a commissar unlike any other stated-fluff depiction of commissar, so that readers will like him), who by the way was not raised by birth in stealth arts and therefore cannot claim "Ghost" level skills in it - he 'sneaks up' on a couple marines in a swamp and cuts them in half. This despite the fact that;

a) An energy field does not a lightsaber make. That is, just because a power weapon can cut through anything, doesn't mean it does so easily . It's just an extreme anology of putting a better edge on your blade. Is it easier? Yes. Can you now slice through metal with the same amount of muscle power as lifting the thing? No.

b) Lyman's ear, *******. From Lexicanum; Lyman's Ear
'Phase 11: Not only does this implant make a Space Marine immune from dizziness or motion sickness but also allows Space Marines to consciously filter out and enhance certain sounds . The Lyman's Ear completely replaces a Marine's original ear. It is externally indistinguishable from a normal human ear.'

This is the author that had a Dreadnaught get blown up with a lasgun, Commissars as the misunderstood nice guys who hung out with re-incarnated saints and the spirits of deceased battle-sisters. And since when was Ciphias considered cannon, or at the very least, not viewed through heavy leanings (as it's written by himself?) I can't remember, but Abnett may well have been the guy who had a human child destroy a Falcon Grav tank with a rock. He's the type. And the thing (that I've seen elsewhere and agree with) is that the DW marine is designed to be horrible when viewed from a rank-3 standpoint. As you move up, he's extremely underpowered.

Now, this hate-post is in now way directed at you people here (well, the hate part anyway), just listing why I think Abnett makes an extremely poor example. Now, I completely agree that 'normals' can kill a marine, I just don't think that they should butcher an ambush, sprung upon thier wedding, in Tau or 'fringe' space, from a squad of Space Marine Veterans selected for this mission. .

Or even want to do so, to be honest. After all, it will be pretty clear that the DW's superiors have been con'd here, so trying to do more than fend off the Marines would be a very stupid thing to do if they ever want to rejoin the Imperium and/or survive after this mission is complete. You have to remember that SM are viewed as mythical Gods by almost everyone, and that's without meeting one. Even those humans that deal with them most regularily would still be impressed with thier abilities and loyalty. We're talking about a group of 'guys' that had track records as long as most Inquisitors before they impressed thier Chapter enough to move to DW, and haven't slowed down since then.

But if that doesnt slide with you, think of them as a resource, such as the Temple Assassins. Fluff states there's less than one of these guys for every planet in the Imperium (as always, your mileage on that may vary, as mine does). Killing off a bunch of them will seriously piss off a whole bunch of people, such as thier Chapters (yes it may take a while for news to get to them, but they've lost a friend, brother and decorated soldier and this isn't a battle or war we're talking about here. They know exactly who to blame, and those people are now fair game. No trying to cover this sh*t up, even your vaunted Inquisition will be no defence etc), thier 'handlers' in the Ordo Xenos, and whatever friends/awe-struck retainers they managed to accumulate over the years of association. Nothing stopping them from getting briefly re-instated to overthrow the corrupt lord, and then executed for Hereitical acts once they're done.

So yes, throwing a half-dozen pissed-off Chapters and Ordo Xenos Inquisitors & Interrogators into the mix is far, far from your best move. And that's just going through it all logically. Honestly, if they're cocky after killing a Space Wolf, instead of still shell-shocked and surprised to be alive, then you weren't playing him right. They should be frightened, in awe, and not want to kill even one person who has a (kind of twisted, many-connections-away) claim to being born/created by the Emperor himself without complete proof. Even if they were able. Like I said, I don't see the Marines sticking round once the situation goes completely to ****. Not to mention, if this is a Crusade against the Tau (or in that area) and they're officially declared Heretics beforehand , then all you'd need to do is include that world in your daily invasion orders, and detail a couple Imp Guard regiments down there to 'cleanse and purify' anything breathing.

And I didn't really think I was playing them as dumb brutes. Quite the opposite, actually; Go with plan, plan is fatally flawed, retreat and regroup, plan some more. Staying until everyone's been butchered is acceptable if they were able to complete thier mission, which they won't and might not even want to once they see hints that something untoward's happening here.

But I do admit that you're closing off avenues of attack here, aka justifying some things and filling in details for me.

By this point in the arguement I think we're arguing over semantics to be honest. Why don't we take a new route to this. I'm using Death Watch, that part of conversation done. Here's how I had planned.

The wedding is being performed in a stripped down former Imperial Church that has been converted to a themed night club inside the Tau Empire, being run covertly by the second inquisitor who is there for his own investigations. The ceremony is small and private as our Inquisitor Domina is performing the ceremony. Things would start off normal, small pre-war wedding a la Independence Day. Perception checks will be rolled to hear roaring sounds from outside. If they get it, they get a bonus to dodging debris when parts of the chuch/club explode inward, (probably killing an NPC right off the bat for a good start). The marines spread out around the church, not completely around, probably the first half, enough to get vantage points through holes in the walls. The Brother-Captain does the ol' "come out and die like good imperial citizens and perhaps the Emperor shall show leniency." I'll probably throw in a "in the name of the Inquisitor-Commandant" for a good information plug. The moment one of the players goes to pull a weapon, the attack will begin. Likely this is to happen before either inquisitor can run any interference. Though, even if they do, I highly doubt the Brother-Captain will be convinced. With the nature of the wedding, I'm debating whether to encourage the players to leave the weapons they can't conceal behind. If they do, I think it's a safe bet that the inquisitor running the place would have a couple hidden caches of weapons.

Either way, the attack begins. The Death Watch announcing their presence lose surprise in the battle so might not necessarily go first depending on my roll. I can't determin how my players will act, half are likely to say run, while the psyker who WENT BACK for the death blow on the Space Wolf before (she had to use fate points to survive) will likely try to use her abilities to fight back, another with four fate points will likely charge in. She has some nice ones that could make the battle interesting, due to unique situations with her character. Like I said, not sure. Either way, if they fight as a group, and all goes well they might be lucky enough to take one down. No matter the case when it comes to the Death Watch's turn the doom shall be brought down. Probably some will attempt to pin while others flank around. I might throw in penalties to dodging giving the DW high speed xenos weapons. Likely by the end of their round players will be feeling death on the door. If they don't run or can't pass their willpower checks to run, there will be plenty of fire coming back at the marines from the entire assembly. Not doing much since the marines will keep their distance. Things will continue similarly, the marines doing heavy damage the doom stew coming to a boil.

Inquisitor Domina who at the outset will be injured by the falling debris will finally get fed up with all of it. Domina is pushing her six hundreds and is rather elderly, but it's only given her time to increase her telepathic abilities. Any marine within vaciniy will mind-die very quickly. Likely the marines will be reduced to three by the time that she passes out from the strain. The other inquisitor having enough himself will order a retreat. If the players attempt to stay to fight they will have to pass will power checks and likely die if they pass them. The DW could persue or fall back to regroup. Liekly fall back as by this time the Fire Caste will be responding in full force.

I may cut the session off their and explain their ways into the next setting or have them do some rolls to evade Fire Warriors picking them up...

Also, as one last note, I did not mean to infer that you treat marines as unintelligent, that was more of a general rant.

Ok, yes, arguing relatively pointless semantics I can agree on. The themed night club made me lol (or snort in amusement, but on the internet that's the same thing). My main points of contention here are that Marines should be an incredibly hard challenge, and that a (as I now know) 600-year old Inquisitor should know better than f*ck with the DW and thier handlers. They're clearly being misled, because otherwise they would be Chaos or at least rebels, which would make them even more dangerous.

Not to mention you have to be a massive-level psyker to mind-death even your average guy (especially at range), let alone the kind of resolute, trained mind a Marine or Deathwatch member would have. They fight Eldar , people. Farseers, anyone? Mindwar ? They know exactly what they're coming up against, is it so hard to believe they might be prepared? Also, as a compromise between your wanting to kill them and me not; They're Inquisitor-level characters. Ergo, Fate Points. You just think you killed them... Plus, they definately rank as boss-level enemies, so going into critical damage for them is a must. Of all marine groups, they're probably the most likely to use the benefits 'playing dead' for a few moments would garner them. (I also believe that out of all Marine-related organisations, the Deathwatch are the most likely to have an Untouchable Marine, but that's my own personal theory.)

I think having to use cached weapons is a cool idea, but it might be a little wierd if the undercover =I= cell managed to keep a selection of plasma- and melta- weaponary hidden in a nightclub. I mean, it depends on what level of control/interest they have on that world/area, but they have an average level of technology that's more advanced than most of the Imperium. Then again, if anyone in particular in 40K would be crazy prepared, it would be an Inquisitor. Just figured it might be entertaining for them to have to use auto/lasguns for a while untill they can scrounge up/scratch build a more effective weapon.

The Deathwatch will go first, by the way. It's called the Delay action. Might be fun to give the Marines a Fear rating of appropriate level, but if they fail they can't move. Something like deer-in-the-headlights, as this is practicaly the most unexpected thing that could have happened. I re-read your post about them killing a Space Wolf, and only now realise he was a scout (they still should have all died, but in a different way. You know Wolf scouts are different from everyone else's right?). Ergo, five or so 8-foot-tall monstrosities decked out in military power armour should scare them witless.

Some non-marinedeath related comments about the fight; The DW would be head-hunting the most dangerous members of the group, so that Inquisitor will be pretty messed up. Xenos weapons could be a good idea, but make sure they're very butch, manly weapons like a scavenged Tyranid Barbed Strangler hooked up to a vat-grown synflesh interface device and wielded like a heavy bolter, ammo-backpack and all. No pansy eldar shuriken or splinter weaponary, please. And again, probably want to make sure the players can't get thier mits on it. Doubt there'd be much cover in there that could stand up to DW-level weaponary, so ducking for cover might not be as instant-win as your players will hope.

And now, more specificaly detailing the DW; Each should probably be a unique character, even though they're most likely all wearing helmets. IE, the Flesh Tearer with lightning claws, the Dark Angel with plasma cannon and robes, etc. Just some touches of Chapter cliche-ism. Do a few test runs on your own, use Purge's marine stats and boost them a little in different directions for the different specialists. If any marines stick to bolters, take a few pages from RT and have them be full-auto capable, maybe with drum mags as well (remember to scale the damage up too, as DH directly states those weapons are for humans; try HeavyBolter dmg). Power armour should also be tougher than the 'civilian' model, giving a bunch of door-prizes along with it like Dark Sight, Auto-Stabilized, Bulging Biceps, probably Regeneration (a lot of sources have practical medi-bays inside that armour and your players should be focus-firing anyway). And considering the only DW options so far in TT have included the option of having a Librarian with psychic-hood as leader.... I plan to list many ways to foil your psychic shenanigans, but hey, I'm taking the role of attack-planner here. The DW would be doing the same.

And yes, I didn't really think you were talking about me when on about marine stupidity, but thanks anyway. Was just confused that you'd at the same time be complaining about that school of thought, yet having your examples be (in my opinion) exactly that. Not that any of us are exactly uncontrary...