hmmm... theres a slight problem with the forest troll animations. see, blizzard didnt put much effort into this (obviously) and the head of the troll wobbles really weirdly in the walk animation.
now this wouldnt be a problem, but all troll kinds have same models and anims (dark, forest, ice). there are basically 2 troll creep models: troll and troll caster.
troll caster isnt bugged like that, but do you like the skeleton troll to have a staff and be a caster?
if you have the possibility you could look at them yourself in magos' model editor