I would change too. It's pointless to face again and again an enemy that you can't kill with the class you're using. I think that each aspect warrior should have upgrades for his equipment, like anti-tank grenades or something like C4. It would make classes more balanced and versatile.
I will most likely "level" up a Dire Avenger (if it's like in PS2 where you have to "level" each class on it's own), and those will be needed in almost every situation, I guess.