So using Warrior of Lossarnach as a marker trims the results quite a bit, though I suppose it leaves out some mostly-Outlands build that run LST and use Beregond for defense. Using the most recent 3-hero deck with that card from each creator produces 40 decks. Here's the sphere breakdown (using a * for neutral)

10 DDD

7 DLS

6 DL*

5 DDL

3 DSS

2 DLT

1 of (DDS, DDT, DLL, DST, DS*, LSS, LS*)

So 38 of 40 used a leadership hero, and 31 of those 38 used Hirluin. Ten were mono-leadership, another seven were double-leadership. 23 of 40 used a lore hero, 15 of 40 used a spirit hero, and just 4 used tactics (3 Beregonds, 1 Elladan).

Most popular heroes by count:

31 Hirluin

8 LeDenethor

8 Gandalf

7 LeAragorn

7 SpGlorfindel

6 Beravor

4 Arwen

4 Erestor

4 LeFaramir

4 Theodred

3 TaBeregond

3 SpEowyn

LeDenethor's high count is impressive considering how little time he's been out. Hirluin-Elrond-Gandalf or Hirluin-LeDenethor-LeAragorn probably represents these decks best.

@PsychoRocka
We don't need only "broken" decks to pass Nightmare Decks or scenario like Battle of Carn Dum.
I have won many Nightmare games with "normal" or thematics decks. I think that a big knowledge of the scenario contributes on victory.
That's makes me said that designer haven't in mind the broken decks but have in mind that expert player will play Nightmare mode.

Just to mitigate some of your affirmation, my Caldara deck haven't a 100% ratio. I have played the scenario one by one until having a victory.
If i win a scenario, i don't retry it but go to the next.
I have recently retried Into Ithilien Nightmare 5 times and my ratio is 40%.

Thematics decks are not equals in the game. Some thematic are powerfull and some other very weak. You can easily do Nightmare scenario with dwarf for example.

Now, we can't put all power decks in the same bag
Some of them are just broken and can be played on auto pilot mode. These decks have an IA and just need a player to put card in play. I call them "no brain decks".
You draw, play cards, quest easily, fight easily and go to next turn. And again, you draw, play cards etc ...

I have build two "no brain decks" :
http://ringsdb.com/decklist/view/811/boromir-ta-glorfindel-sp-gandalf-2.0
http://ringsdb.com/decklist/view/1251/the-rapid-charge-of-outlands-2.0

The first one, you draw, equipped heros, quest, fight and win ... Ratio of 100% on Into Ithilien NM on 10 attempt. It have passed most of the NM quest without any difficulties.
You can modify it with Gondorian Fire and Blood of Numenor to make a seastan's like deck.
I have stopped playing it because it's boring ... Game are always the same.

The second one, you draw a lot, generate a lot of ressources, put a lot of outlands and win the quest very quickly.
After having win Battle of Five armies NM on the 4th turn, i have stopped playing it. It's like putting your brain outside of your head and let the deck win alone.
My knowledge of a scenario is useless with this deck ... So boring.

Now Caldara is very different ( http://ringsdb.com/decklist/view/2452/the-song-of-rebirth-1.0 ). Each game is different (Caldara can be agressive or purely control or a mix), the player skills are also very important.
All victory are very intense. I am regulary near to be defeated. My strategy, my knowledge and my choice give me victory.
My victory on The Three Thrial NM was totally epic ... I was near to loose three times. Yesterday, i have beaten Chetwood Intruders NM but i was at 47 threat near to loose too.
Unlike the previous deck, when i play a scenario, it's very intense.
The scenario have a chance to beat me and i have a chance to beat it. It's fair.

One more thing, i have played all nightmare decks multiple time (and take a lot of defeat). I have a good knowledge of each NM version. I have beaten Fundation of stone NM on my first attempt because i know precisely how the new reset works. I have prepared my board, my discard pile and my hand on the two first step. So the reset wasn't painfull, then i have volontary kill Galadriel in order to have 4 questing Heroes (Caldara, Prince Imrahil, Arwen Undomiel and Sword-thained ally) for the 5th step and so increase my questing power.

Some powerfull decks are just no brain and boring but others are just fun making each game very intense and interessant.

@Some Sort
The best line up for Caldara decks is Arwen Undomiel/Caldara + Galadriel. Eowyn or Cirdan could replace Galadriel, but the deck will be weaker.

Looking on the most recent 3-hero decks using "Entmoot" from 68 creators, I get the following sphere breakdown:

17 DLT

17 LLT

9 LTT

8 LLL

7 LLS

4 DLL, LT*

3 LS*

2 DL*, LST

1 LL*, DDL, LT*

So an even split between DLT and LLT. Six of the DLT decks were iconic Sam-LoPippin-TaMerry decks, which makes some sense -- secrecy gives time and resourceful to pay for and build up an ent army, and ents are the most powerful tribe you can associate with the hobbits. Even more common is LeFaramir-Bifur-Mablung, combining Faramir's readying goodness with a resource generator and a resource grabber.

Treebeard himself is in 21 of the 68 decks, so ally Treebeard is far more popular. His thematic association with Merry and Pippin continues in many of these decks, as 30 of them have Pippin (all Lore Pippin), and 27 have Merry (20 tactics, 7 spirit)

Most popular heroes, minimum 3 appearances:

30 LoPippin

21 Treebeard

20 TaMerry

17 LeFaramir

16 Bifur

14 Elrond

13 Mablung

11 Gandalf

9 Mirlonde

7 Grima

7 Haldir

7 Legolas

7 SpMerry

6 Sam Gamgee

5 Beorn

TaEowyn is in three decks so far.

Eagles: Mablung is obviously MVP because of how expensive Eagles are. Leadership Denethor is also a huge champ-- he can pass a resource to Mablung to help pay and he gives you Steward access, as well as Sneak Attack for your Descendents. I'd probably go Mablung / LeaDenethor, and then either TaBoromir (to maximize the usefulness of Support) or T'Eowyn (for questing / keeping your threat under control).

Starting willpower seems scant for a LeDenethor/Mablung/TaBoromir build, though with Steward and the initial extra resources it can get out some questing allies. LeDenethor/Mablung/TaEowyn can start questing strong.

I looked through ringsdb for three-hero decks with "The Eagles are Coming", looking against at the most recent build by a creator. Since I'm interested in a solo lineup, I figured that all the mono-tactics were multiplayer unless they have TaTheoden or TaEowyn in them -- and of 25 monotactics decks that would otherwise qualify, only one fit that criteria -- my "Dori and the Eagles", which isn't meant to be a solo deck (TaTheoden-TaAragorn-Dori, with the other deck being a hobbit deck that churns out the non-tactics attachments that can make Theoden and Aragorn shine.) There *is* a TaEowyn-TaTheoden-Eowyn deck that uses Eagles, but it was supplanted in this analysis by a more recent DTT Eagles deck using Imrahil-Boromir-Hama.

So ignoring the mono-tactics, there were 37 most recent decks using "The Eagles are Coming". A lot of those (like Imrahil-Boromir-Hama) don't have much questing power, but by having non-tactics they at least have access to some, though it's likely many of the decks analyzed were meant for multiplayer. Here's the sphere breakdown

15 DTT

6 STT

4 LTT

3 DDT

2 DLT LLT, LST,

1 DST, DLL, SST

Yes, there was a DLL deck. LeFaramir/Bifur/Beravor, a Ent/Eagle deck with Narvi's Belt, Good Harvest, a Song of Battle, Radagast, and Treebeard. So the most popular eagle deck is double tactics with leadership splash. Here's the popular heroes (3 or more required)

14 Legolas

10 TaBoromir

10 Mablung

7 SpEowyn

6 Imrahil

5 Gimli

4 Beorn

4 LoPippin

4 Theodred

3 TaAragorn

3 Bard

3 LeDenethor

3 LoDenethor

3 Eomer

3 LeFaramir

3 TaMerry

Because the Eagles are available first cycle, we see Legolas as the most popular tactics choice and SpEowyn as the most popular off sphere, in 7 of 10 decks using spirit (SpMerry, Arwen, and Cirdan took the other three spots). With the full set, I think TaBoromir-Mablung-Imrahil is probably a more stereotypical lineup.

@13nrv

Yeah fair enough I guess I didn't read about your Caldara deck in enough detail but if that is how it operates then fair enough it doesn't seem as though it is one of what you call the "no-brains" decks. You do however go on to say you do have two of those decks. If Caldara decks aren't as foolproof or unbeatable/infallible as I thought they were then I have nothing against them.
Those other two decks of yours that you mention though are where my issue lies for sure.

I stand corrected re your Caldara deck however!

A quick summary of the most recent Twins decks -- who is the favorite other hero?

My sample was 43 decks, 16 extra leadership, 2 lore, 18 spirit, and 7 extra tactics. No Gandalf.

Here's the leadership choices:

5 Halbarad

3 Amarthiul

3 Denethor

3 Theodred

1 Aragorn

1 Balin

Halbarad's the top choice, probably for a multi-player combat deck -- since the brothers don't start with Ranged & Sentinel, make the enemies come to them. Amarthiul has the right two spheres coming for him, but again is probably for a multiplayer combat deck. Theodred/Denethor/Aragorn/Balin could make a good solo deck.

Only two decks with Lore:

Aragorn

Grima

Alas, the most recent sample doesn't have the thematic Elrond/Elladan/Elrohir

Spirit was the most popular sphere:

9 Arwen

3 Eowyn

2 Cirdan

1 Eleanor

1 Galadriel

Arwen seems perfect for the solo brothers deck -- good quester, can give resources to either resource-wanting brother, and a perfect thematic fit.

Tactics:

2 Aragorn

2 Legolas

1 Bard

1 Beregond

1 Theoden

Except for the deck with Theoden, likely multiplayer combat decks. Aragorn, like Halbarad, helps solve the lack of ranged/sentinel. The Bard/Legolas/Beregond decks solve it the other way, with a backup plan.

Took a look at the 47 most recent (by author) decks featuring SpTheoden. I was expecting SST to dominate, but it didn't:

10 DSS

8 DST, SSS, SST

5 LSS

3 DDS

2 STT, LST

1 DLS

Having at least two spirit heroes was common (31 of 47 decks), but leadership was in more decks (22) than tactics (20). The reason seems to be in the heroes, only Eomer was a popular choice (for thematic and ability reasons both) while Theodred, Elfhelm, and Erkenbrand were popular picks in leadership.

Heroes selected at least three times:

24 SpEowyn

14 Eomer

8 Elfhelm

8 Theodred

5 Erkenbrand

5 Grima

3 Dunhere

3 Eleanor

3 Galadriel

3 Hama

Despite SpTheoden's ability only relating to Rohan allies, there's a strong preference for Rohan heroes in the Rohan deck, with only two non-Rohan heroes managing even three picks. The most popular lineup is also likely the most thematic, SpEowyn-SpTheoden-Eomer.

Examining decks containing both Visionary Leadership and Leadership Boromir (e.g. Gondor decks). Here's the sphere breakdown for the 50 decks:

20 DDD

14 DDT

12 DDL

3 DLL

1 DST, DLT, DDS

And here's the heroes chosen at least three times to go with LeBoromir:

27 LeDenethor

9 TaBeregond

9 LeFaramir

9 Imrahil

8 LeAragorn

5 Erestor

5 Mablung

5 Theodred

4 Balin

4 Damrod

4 LoDenethor

3 LoAragorn

The far and away favorite is LeDenethor, found in a little over half these decks despite his recent vintage. The stereotypical Gondor deck would be the very thematic LeBoromir-LeFaramir-LeDenethor.

Took a look at decks using "O Lorien", figuring that while Celeborn is the iconic Silvan enabler, he is a global enabler and could (like Dain) be in a multiplayer deck that isn't really a Silvan deck. Meanwhile, anyone using "O Lorien" without Celeborn has committed to playing Silvans. I found 52 decks.

Sphere breakdown:

14 DLS

8 DST, DLL

6 DLT, DSS

3 DDL

2 LS*, DTT

1 DDD, DDS, DDT

Most popular was DLS, and the most popular combination was obvious also. Here's the heroes selected 3+ times:

42 Celeborn (10 decks without him)

26 Galadriel

21 Haldir

7 SpGlorfindel

7 Legolas

6 Elladan

4 Erkenbrand

4 Imrahil

3 Elrohir

3 Erestor

3 Mirlonde

3 Rossiel

3 Theodred

Elladan appeared in six decks, Elrohir in three, clearly some of these were meant to be multiplayer. How important is theme? While 17 decks used tactics (two double tactics), just two of them elected to give a spot to Eomer, whose attack is buffed by allies leaving play.

The stereotypical Silvan deck is clearly Celeborn-Haldir-Galadriel

Looking at decks including To the Sea, to the Sea -- that's not necessary for a Noldor deck, but the presence of the card is a sure indication that it is a Noldor deck. There were decks from 44 creators. Sphere breakdown:

15 LSS

9 LLS

5 LST, DLS

2 DDS, SST, DSS, SSS

1 DST, LLL

Here's the heroes appearing in at least 3 decks:

31 Arwen

21 Cirdan

17 Galdor

16 Erestor

6 Galadriel

5 Elrond

4 LoAragorn

4 SpGlorfindel

3 LeAragorn

3 Eleanor

3 Elrohir

The stereotypical Noldor lineup would be Arwen-Cirdan-Erestor or Arwen-Cirdan-Galdor.

I like Easy Mode. Well, Sleazy Mode.

... what's Sleazy Mode?

I like Easy Mode. Well, Sleazy Mode.

... what's Sleazy Mode?

You start with the extra resources on every hero like in easy mode but keep the encounter deck untouched. Then it's more like a normal game because the encounter deck can throw it's combos against you but you start with more cash in the bank thus having an easier start into the game for setting up your board state.