While I would like to see some of the movie Trolls implemented, it wouldn't be the case to overpopulate Mordor even more.
As said before, I'd rather see Trolls implemented in the Misty Mountains, with the following criteria:
-Moria fornishing Cave Trolls; average price, highly versatile, both melee and long-rage, but weaker than Mordor's Mountain Troll. That's the classic and it should stay that way
-Gundabad giving off their own version of Attack Troll; high price, damage slightly higher than cave troll with tree trunk but very high armor, but as slow as Ents
-Goblintown gives access to Troll Catapults; the most mobile siege engine in the game, more ranged damage than Cave Troll with boulder, but far more vulnerable (the most squishy siege unit I'd say)
As stupid as some considers most of these creatures to be, it's actually very functional: those engines were built and supposed to move along tunnels, be they worm-made or Goblin-made, regardless of the Worm's concept being acceptable or not. And you simply
cannot move a wheeled catapult in a tunnel..but if it has legs, then that's different. And it's operated by Goblins (Goblintown's specifically) whom are shown to be even slightly shorter than Dwarves. Even the Troll Ram, however stupid it may seem, made sense: a quick way to bring down a wall and get inside. Those armies were made up very fast, kind of like Isengard, but in an even more desperate rush, and with whatever could be found around.
I know that the main siege unit for the MM are supposed to be the Giants, but of those I was never convinced..
As for Trolls size, I'd say to stick to Cave Troll size. In the movie they might have looked bigger, but I believe that was more for the fact that they had Goblins on their backs and were facing mostly Dwarves. But even if they were bigger, I don't see the problem: many abominations did Sauron create, and these Trolls were even more twisted to give the feeling that he was really making out his armies with whatever he could take.
Sorry for the disgression, but I wanted to let this point known.
As for Dol Guldur/Minas Morgul functionality, it's actually all a matter of what you want to play. For exemple, in certain occasions you will need one of the two first. Against Elves, you might prefer Morgul Orcs, if anything for more durable arcers with flaming arrows, even if poison damage might very well counter Elven healing.
Against Dwarves, you need Dol Guldur for a simple reason: Khamul and his demolition band. In a siege, I find little more important than having Khamul around: you just need to park him outside enemy walls and watch them crumble. That said, Castellans are also very useful, spiders, on the other hand...
BUT, a summoning spell that calls help from Dol Guldur is fine for MM, so we can have the whole Hobbit feel.
Yeah, PJ and crew worked on a schedule that was not tight, but blade-thin, so i am quite content with what came out
and honestly, if those are Moria Orcs, they could just be a different breed: technically Azog had taken Moria, wouldn't make little sense if some Gundabad Orcs moved there as well. They probably didn't dwell deep enough to meet the Balrog, as they still had normal-sized eyes and could not scale walls..but I disgress
