I'm with DG on this. With the mage, you need some good artifacts when you start. I won't even try to start a game without the Ancient amulet so some serious sneaking is required to get enough cash to have that in your starting gear!
Also even with some good stuff, until you get Level 3 Chaos. Level 3 Destructive and your intellect well over 30, you're not doing a great deal of damage with your spells!
The problem with higher magic is that you have to cast a low level spell first. This means you can't for example cast phantom and then buff the unit with a lower level spell like mana spring or stone skin. (Unless of course you use a lower level of the phantom spell but then the stack usually gets wiped out before the end of the first round!)
