AI spell casting priorities

[Tuidjy]

I hate Touch of Madness. With a passion. It should never be cast unscripted.
I never leave a mage unscripted, but I know that if the AI decides that a nature
spell is not worth the gems, it will default to Touch of Madness, and send
archers or mages into the fray. At the end of the battle, the number of
casulties precisely matches the number of targeted units.

And not a single gem should be used against a retreating enemy, ever. What
really sucks, and I have seen it happen at least once, is when the AI decides
that it does not need Arrow Fend when I am storming a castle, but once the
enemy has routed, summoning some Air Elementals is a damn good idea. Arrow
Fend, by the way, is one of the spells I'd love to see as "scripted only".
If you can't be bothered to script it, you should not benefit from it.