I played as a mage. I quite say that he is in quite at a disadvantage. You would need lots
of mp potions (cause it doesn't really give that much) and hp potions (since there is 2 turn cooldown on heal). Necromancy summons are too weak. Skeleton dies too fast and you can't use potion on it but you can use heal (but then again after 1-2 turns its dead (heal can't catch up) this problems goes to spirit also. Also, enhanced summoning doesn't really look like it helped at all.