Originally Posted by
Withwnar
A couple of posts said that elephant trolls would run amok. This is true only if they are given the can_run_amok EDU attribute. Sauron and Ents do not have it and do not run amok.
Cavalry and elephants also cannot climb stairs, so they can't get up onto the walls through doorways/towers nor, even worse, exterior stairs that some custom settlements have (e.g. Isengard) which should be no problem for trolls.
Trolls climbing ladders and siege towers is a bit silly but it is the lesser of two evils.
Also, I'm no unit expert but as far as I know elephants/cavalry can't man artillery; Troll Catapult trolls must be infantry. If that's true then you'd end up with some trolls that can climb ladders (catapult trolls) and some that can't (regular trolls).