Maniac
Apolyton Sage
Right now thats the best way, better to left them burn out than have an AI constantly running back to put out a forest on the infernal borders (and will just catch fire again anyways).
I think I'd just keep a couple water adepts constantly near the borders.
But after we release, you guys do all your playtesting, we tweak and get everything working as we want we will look at teaching the AI to do the same kind of tricks you guys do.