IMHO Immobile Treelords are pretty useless...and additionnal measures to keep them totally immobile (no misc for example) only make this worse.
And why should they be immobile ? They're trees, but magical ones ! Tolkienite Ents do move eventually, so why Dom Treelords couldn't ? "Natural" explanations such as "trees don't move" are out of place here : did someone ever cross an Ice Devil IRL ? Still I see them in every game I play !
