It wasn't any easier. I tried it with a mage who had both spirit healer and arcane warrior (and had Mana Clash), and most of the monsters were immune to just about anything I threw at them.It was nice actually having to use tactics - potions and all sorts of things to stay alive. Though I id say if your main char was a mage and spirit healer or arcane warrior the last boss on NM mode would be alot easier!
I really enjoyed the phase approach to dungeon design, though.