You are making this game WAAAAAYYYY too homogeneous.
ALL classes SHOULD be different.
They should not ALL be able to self-heal/deal damage/heal others/avoid(disregard) traps/CC/buff/etc/etc/etc....
This game has been made into a Min/Max game (ie. an MMOPG) instead of the MMORPG game it is supposed to be.
Stop BALANCING the classes/trees and make them specialized as they are supposed to be.