Yeah, you are right, they could be implemented as a temporary summon. Actually there is still one spell which can be replaced which you already mentioned-"Untamed Alliance" or whatever this is in English, I'm talking about the spell which allows the taking of creep camps. This ability is essentially not usefull any more, because the "Hoard of the Grey Mountains" ability is gone and Misty Mountains can already built most of those creep hoards on their settlements. So there is in fact space for a troll summon (and yes, you are right again: Even Misty Mountains armorers can built simply bigger armor.
)
Also, concerning Misty Mountains, temporary armored trolls would actually be pretty interesting and the Hobbit design which was discussed here, looks pretty neat, I have to say.
(Especially because it looks more primitive than the Mordor troll armor -the helmet looks just like a rock that got attached to this poor trolls head...
)
2-3 armored trolls are probably to much though, but the balance can of course be adjusted later, also there could be a system like the spell evolves during the game, starting which only one troll so Misty Mountains (I everytimes spell the entire name, because MM is reserved for Minas Morgul
) can't just spell-trollrush the enemy, but still keep them as a useful summon later. I'm just making a wild guess, that should be our smallest problem right now.
Again, I really don't know so much about MM palantir of powers, so this is very informative discussion for me at first place.
It mostly stayed the same. Spiders got of course replaced by a very nice spell which summons an inactive, temporary tunnel exit from which various orcs emerge. Tainted Land is a tier 1 spell now, it's old position got replaced by Scavanger and the war cry got replaced by War drums (the old building with the troll). So their power menu looks like this:
Tier 1: Bats, War Drums, Tainted Land
Tier 2: Drums in the Deep, Scavanger (passive), "this tunnel spells whose name I forgot", Untamed Alliance
Tier 3: Awaken Worm, The Watcher, Darkness
Tier 4: Dragon Strike, Balrog
Greetings
Melkor Bauglir