Yes, a mage with 9 levels and spellcraft can be a pain. I would not shrink the PK range with our current playerbase, but a possible tweak to the level difference with regard to spells might make sense.

For example:
mage has one level on you +5 with spells,
2 levels +10
3 +15
4 +18
5 +21
5 +23
6 +25
7 +26
8 +27
9 +28

So, you're still at a disadvantage, but the penalty/level is not a line graph, but a curve.