Now back when a physical tree being on the table was a possibility (Bard still has a possibility) it wouldn't have been so bad for Polymorph to use INT afterall it is spellcasting.
But given that it isn't going to happen and a hybrid system (Int + Str) isn't likely.
I think Polymorph which is a skill involving transforming your body then lashing out should use strength. It fits mechanically and thematically without losing anything other then another intelligence spellcasting skill tree (which we have way too much of)
Given that strength ONLY has Marshal, this is desperately needed
