An objective look at...objectives
So objectives are kind of a big deal. They can turn a narrow victory into a route or a close game/minor loss into a win. Being able to both select the right objectives for a fleet and select the right objective of your opponent's can win you games almost by itself. Lacking a good objective regime gives your opponent no real reason to not just take first activation and may even give them an edge over you. All objectives can be broken down by 3 core attributes:
Tactical
Bonuses like this just help once the battle is joined and tend to most commonly come in the form of adding dice in some way. These benefits tend to be the least powerful and most easily mitigated by good play. These should basically be treated as minor bonuses/drawbacks and should take a back seat to the other two attributes. A good example here is the extra dice in opening salvo or the removal of accuracy results in solar corona.
Strategic
Strategic aspects allow you to dictate on what terms the battle will be fought. They are persistent and far more difficult to mitigate than tactical attributes. Strategic bonuses can allow your ships optimal firing positions and force your opponent into very suboptimal ones making favorable trades for them far more difficult. Dictating the terms of the engagement is powerful in a game like Armada where simply traveling to the point of battle can take 1-2 turns and turning around to make another attack run is largely too lengthy of a process to do before turn 6.
Victory Points
This is without doubt the number 1 thing you should look at when debating missions. Tactical and Strategic bonuses are basically the middle man as they're just helping you work towards getting more VPs than the other guy, whereas things that just give you VPs are far more direct and powerful. To put this into perspective, imagine a completely bull mission that just gave one player 300vps. That player literally doesn't have to do anything but not die and they get a 10-1. In this respect, VPs can dramatically change your strategic and tactical picture by forcing you to make far more favorable trades than normal just to break even.
-Not all VPs are created equal
Almost none of the missions give out a symmetrical number of VPs. A few of them, like Dangerous Territory, have a flat pool of VPs available to both players, but most objectives that give out VPs to both players operate on an asymmetric basis i.e. one person has more available than the other. Most Wanted is the biggest culprit and frequently player 2 will select the cheapest ship they have and the most expensive one you have. Not only are more VPs on the field for them, but the mission also makes it easier to pick up those VPs. The most dangerous objectives by far are the infinite VP ones. The VPs you can get from the things like Precision Strike, Superior Positions or Fighter Ambush do actually have a cap, but the cap is so high that you might as well treat them as infinite VPs missions. It's very easy in these missions to end up so far behind the other player in VPs that you need ludicrously good piece trades to even be in the fight. Fire Lanes is another example of interesting VP distribution in that, while the VPs are technically available to both players, realistically, player 2 is probably getting all of the fire lanes on turns 1 and 2 putting player 2 in a position of immediate deficit. Outpost Assault is the most obvious example of simply giving VPs. There are 80vps available to both players, but all of them start in the hands of player 2 meaning that if no dice are rolled by either side, player 2 automatically gets a 7-4 win.
So to take an example from a fleet where I really don't have to burn too many brain cells to talk about, let's go with my current Rieeken build, the Magnificent 7 and break down its three objectives:
-Fighter Ambush
This mission has no tactical side. It offers no direct benefit when combat is joined. It may seem like it has a strategic aspect because you deploy squadrons after everyone else and anywhere near obstacles, but that's an absolute trap outside of oddball situations. If I had more relay and my opponent had zero squadron cover whatsoever, and a relatively slow fleet maybe, but I'd still be fighting well away from the Bomber Command and Toryn and flak becomes riskier without Gallant Haven (not to mention the lack of dice fixing would make the process slower and hence make the squadrons more vulnerable to flak). In short, the possible strategic side is hard to utilize without boning yourself. The VP side, on the other hand, is an absolute warcrime. Getting 15 vps every time a bomber attack puts a damage card on an enemy ship adds 50-100% vp value for every ship you take down with bombers (which is everything, by the way). An ISD or MC80 would easily be worth 200-250 vps under fighter ambush meaning I can make absolutely stupid sacrifices, but as long as I get bombers on target without getting tabled, I'll still 8-4 - 10-1 the other player. Interestingly, while the VP's are theoretically symmetrical and infinite (either player can get it by delivering bombers on target), they really aren't. It's so hard to deliver bomber strikes through the squadrons, even when the enemy has intel, that it might as well not be symmetrical. Even against other bomber heavy lists, I rarely suffer more than 1-2 attacks from squadrons that put damage cards on ships. So for anyone who's going first and sees this mission pop up, unless you're super confident you can beat your opponent's bombers or that you can table them (and even then your MoV will probably be garbage), this is an absolute no go.
-One thing I will say about Fighter Ambush as an addendum, there's a tendency in Armada that I call "Pinata Syndrome" where players take a ship your opponent really wants to kill or basically has to in order to not lose (Yavaris, Demolisher, Avenger, Gallant Haven, etc.) and put extra crap on it or make it mission ships or flag ships. Basically it's a ship you were going to hit as hard as you could anyways and with the biggest stick possible and the extra points are just giving you free VPs for succeeding, hence the term. Fighter Ambush turns EVERY ship you have into a Pinata.
-Station Assault
Station Assault has 1 tactical benefit of note, that is, only player 2 can repair things on the stations. If you have never fought Luke/Wedge/Biggs/Jan under Gallant Haven when they can constantly repair, you'd be forgiven for not understanding how much of an atrocity it is to make the central combat point not 1, but 2 stations that they can use and you can't. Barring that though, the major strategic element is that you pretty much get to dictate the terms of the engagement. You start deploying obstacles, sans the stations, so that only leaves player 1 with 2 obstacles to try and block potential placement which makes it quite hard for them to meaningfully stop you from just putting them both in a corner and basically telling player 1 "We're fighting here and if you don't like it, though ****". The VP aspect is not the biggest, but it does basically start player 2 with 80vp so they're at 7-4 territory even if no attack dice are rolled. If player 1 breaks a station by dealing 10 damage (enough to kill most small ships barring defense token/accuracy considerations) they get back to even. That's right, for putting that work in, their reward is that they're not losing VPs to the scenario, but they still aren't winning the mission unless they do it again...and they get 80VP. It's jumping through flaming hoops for a ham sandwich. Player 1 has to burn through 20 hull to get the same VPs as they would for a stripped down assault frigate. I won't say never pick this mission, but it does offer lots of little advantages to player 2 that add up, and while none of them are individually untenable, the combination can make the game highly problematic to play effectively. The most dangerous part of Station Assault, hands down, is how unassuming it looks. Everything looks manageable...until it isn't.
-Superior Positions
Superior Positions has no tactical element. The strategic element is that you get to see the other players entire deployment before dropping anything down. This has a wildly Variable impact from fleet to fleet. Fleets that depend on mass guns, have multiple small ships, etc, really have a hard time with this as it's very easy to counter deploy in such a way as to attenuate their firepower down to a more manageable level. It's possible for them to get past this, but they end up doing mental gymnastics and deft maneuvering, while you can just chill in whatever formation and on whatever approach you want. In short, they have more opportunities to fail than you do. Fleets with small numbers of big ships or tight formations can have their own interesting problems as you can force formations to bend over backwards by moving to engage in a way they aren't naturally oriented to deal with and, again, they run the major risk of getting their firepower attenuated and coming at you piecemeal (which if you've ever flown against bombers, you'd know can be fatal). Taking full advantage of the informaiton of knowing where the enemy is going to be does require knowing how ships move and what attack posture they're best suited for, but with some practice, it's not that hard. The VP aspect is interesting. Like Fighter Ambush, it's theoretically symmetrical and infinite, but typically a fleet packing this either has squadrons or lots of smaller ships which can much more easily force you into splits or just drop in your back arc when you move to engage which can actually make this worse in some ways than Fighter Ambush for VPs (even hitting shields gives you VPs and redirecting to other hull zones just lets them get more off of you). Superior positions looks bad, and it is, but parts of it can be mitigated with good play. The major question to ask yourself if you're player 1 and you see this is "How bad is it if my opponent can precisely counter deploy?" This question will very directly give you the answer to whether or not you can afford to pick this mission.
A sufficiently strong objective regime for your fleet can mostly or completely mitigate the first activation advantage and when going first selecting the right mission from your opponent's pool can be a absolute game winner. In an ideal scenario, Player 1 shouldn't be choosing the best objective, but rather the least horribly unfavorable one.