I've been thinking about it, and have several points I'd like to bring in.
First of all, as a general issue, we should be carefull not to make avatarless Balrog too strong, or all overt minions will want to play it. Balrog specific cards (and the character rule) are very good, the only drawback for playing Balrog is the fact that he's popular. So if we compensate the disadvantage of not having a powerfull avatar, the alignment gets too strong. Really, if you have a chance to play a company of Buthrakaur/Hill Troll/Hill Troll/Grimburgoth, a free ally and easy faction at Moria, and People Diminished/Smoke on Wind on same site, why play regular minion at all? Only because you have no avatar...
Second, for this reason and thematic reasons, I think letting the leader count as Balrog is too good, even without Fana cards. Not just the MP cards, which will be harder to play without Flame of Udun, though I think Buthrakaur with Tongue/Whip and some Report You's still has a good shot. But also the support cards, like Angband Revisited, Vanguard of Might, Obey him or Die, Great Troll etc. And like I said, it's thematically unsound to let a leader carry the Balrog's whip and sword.
Then, I still have thematic reservations against the men factions. Personally I was already apalled when ICE introduced Beornings for minions, but to sway them over to the Balrog is even worse. Also, why should the Southrons work for the Balrog, or the Woses? Hillmen? fine. Dunlendings? okay then. Woodmen? debatable, but the rest of them?
I would like to propose another resource strategy, that's kind of linked to the Hobbit:
Crack in the Wall V
- permanent event
Playable on a company containing a Balrog specific leader if The Balrog is not in play. If at Goblin Gate, the company may attack a hero company travelling through High Pass during opponents movement-hazard phase, or at a site in High Pass or its adjacent regions during opponents site phase. After the attack, replace the company's site card with the site the hero company is at or travelling to.
Additionally, once per site phase, a Balrog specific leader at Goblin Gate may play a non-unique wolf ally from discard pile, or he may attempt to influence a wolf faction, subtracting from the roll the number of contiguous regions between High Pass and the site where the faction is normally playable (excluding the regions containing both sites). Wolf factions count as orc factions for the purpose of Great Army of the North and may be played at a tapped Goblin Gate. Each wolf faction you have in play reduces the prowess of any attack your companies face while at sites in High Pass or its adjacent regions by 1.
It's like a combined Orc Mail, yet limited, and Hour of Need for wolves, with Grond effect. All you have to do is make Baduila a Balrog Specific leader with OttS.
Thought about adding Moria too, but it would get too much on the card. Perhaps stick to the attack part only then? I dislike the fact that this also promotes squatting, and I have thematic reservations about attacking companies at Rivendell and Lorien. But the attack would still get cancelled, and it's nice that you can travel without getting hurt by hazards to Rivendell though...
Of course Balrog already has a lot of wolf-decks, the theme link is obvious, but the factions don't get played, nor do the dogs usually do anything except bark, they don't bite. This card suggests you use them in the attack. Perhaps we can also virtualise Our Own Wolves...
The rolls for the wolves would be at minus 0 for Misty Mountain, -2 for Forochel, and -4 for White Mountain, if you don't count regions containing both sites. Great Army would give +1, you'd still need serious help and a stiff roll, but with Threats, a balrog leader would need a 3/6/8 respectively, that's not too bad, and it's not counting the fact that you might get some bonus if you play Goblins/Ice Orcs/Misty/Dunlendings first, though that's not always easy of course.
There are other ways to boost a Balrog warlord in good old fashioned evil ways, perhaps play Two Headed Trolls/Great Trolls at any underdeeps sites or Moria even with a card, and discard them if they don't move for 2 turns, so that you have to use them and not squat with them. That way you maintain some Troll feel, and you got a way to deal with having less influence...
I once raided the Blue Mountains with Bumi/Bolg/Ulkaur/2 Hill Trolls and 3 Two Headeds, while played 2 Descends and 3 Report You's, so that's 8 chars with at least 10 prowess. Opponent was too scared to throw anything at me with an *
I like a war preparations theme for a balrog warlord more than just faction gathering, to be honest. And covert balrog might sound funny, but it's just crap. Maybe certain men factions (hillmen/dunlendings) can be used to make war preparations, like tap faction to make weapon major item playable at tapped site where faction was played, or something.
Stone-age did not end because man ran out of rocks.