GURPS Man to Man.... how to add magic?

[Giovanni]

Me and a couple of friends of mine want to use GURPS Man to Man as a fantasy skirmish wargame....
how we can add magic?
The natural way should be to use GURPS Magic 3e but I suspect that a lot of spells require the Narrator judgement to be applied and are so not suitable for a wargame (where there is no impartial Narrator) plus the prerequisites sub-system make the magic PC creation procedure too long.

What I'd like to obtain from this discussion is...
1. a subset of the spell contained in Magic 3e: each spell in the subset should be usable in a wargame.
2. a way to buy those spell as skills ignoring prerequisites.

or... since in GURPS 3e and 4e there are a lot of alternative magic system, you could suggest something simple that could work in wargame....