I haven’t looked at anything Wrath in a long time so watched a few videos.
Seems like a core 10 covers near everything?
Prot and Holy Paladin
Feral and Boomkin
Enhance
Combat
Arcane
Demonology
Disc Priest
Ret?
I think that covers everything, but maybe not the strongest versions?
Then add a few more heals and whatever the min/max pumpers are to get to 25?
I’m surprised to see there isn’t a DK in there anywhere. Granted, I am more familiar with 25 man raid compositions. There’s a good raid composition tool on reddit (gasp) though I don’t recall if it covers both 10 and 25 man or just 25 man. Might be worth sniffing out.
I may have missed it, but it looks like Frost DK = Enhance, and only Blood DKs get Hysteria?
While Feral brings the bleeds and pack buff?
Again not sure what’s optimal, which is why I ask. 
I would not want to play Demo for the entirety of wotlk, my condolences to any warlock that gets forced to.
You should do 25 players; apparently raids will share lockouts from day 1 instead of later on in wrath.
10 players loot is poop, you need the 25 players loot! (heroic)
I thought it was normal/heroic, being locked? Either way.
If the 10 is correct, 25 would just be a few more of the BIS healers (Holy Paladin/Disc) with a Resto Sham if Tide is worth, and a Resto Druid for the resource rejuve?
Then whatever the S Tier DPS are.
It’s why I have hated the ‘bring the player’ changes since Ghostcrawler pushed them. It leads to more min/max, not less.
Just look at what happened with Fury Warriors in Classic.
They haven’t said this.
They’ll more than likely just split it between 10 and 25man. Two lockouts per raid per week.
This is what I assumed as well.
It’s going to be a physical dps group.
DK for the haste buff to melee,
Warriors and Rogues to dominate charts
Paladins for some buffs
Shamans for buffs
Maybe a priest?
To put it more indepth.
1 DK tank w/ 20% melee
1 Prot Paladin (not sure how many fights need 2 tanks though)
2 Fury Warriors
2 Rogues
1 Holy Paladin
1 Ret Paladin
1 Resto Shaman
1 Disc Priest - can be another warrior or rogue if heals are good
Can’t wait to min/max for the pinncale of 10-man raid difficulty: Naxx10
I think this misses the Max buffs of Enhance/Frost DK, but I’ll check.
Blood dk specced into frost gets all those goodies.
My composition tool said that shamans don’t bring anything not brought with that group, but it could be dated/wrong.
I had an enhance in there, but took it out and nothing left buff wise.
Titans Grip Fury Warrior…
Ah OK, that’s perfect then.
Unfortunately there is no escape under any Blizzard system from “The Meta”
Group based buffs like TBC and Vanilla favor shaman meta, Wrath based+ favors BiS peak numbers pumpers only.
This is the problem with “big bosses” that allows big sustained damage.
also a problem with how systems like WCL and how people read the data.
If blizzard was wise, they would have built something like WCL in early Vanilla and showed total player contributions; those contributions not only of damage or healing, but things like not taking damage in the first place, interrupting spells, the calculated impact of things like Blessing of Kings, WF totem, etc.
All of those things are important, and not counting them only lends to Zug brain disease.
Most of us aren’t going to take any 10-man boasting seriously. 10-man in Wrath is the LFR training wheels mode. WCL shouldn’t even bother allowing it tbh.
True or not, it seemed like 10 people was enough to cover every buff/debuff.
The point is, what’s the best core, to then build a minmax team out of.
I think there are a few encounters on 10 hero that are harder than 25 hero, but I dont know because i never got into 10 players raid when 25 was where the good loot was at. That information i present is based on something I read a very long time ago so take that with a hearty helping of salt.
You’re not going for mounts?
Or titles?