There seemed to be some demon lord behind the mages, so it's possible that as long as a chaos orb is used, the higher chaos creatures will know. Kind of as long as you buy an American CPU in our world, the NSA will have an automatic way to get in, no matter who built the rest of the PC/mobile device.

But yeah, it's pretty strange they didn't even seem to make any effort. On the other hand, I don't see how the mage academy could fare so well either in this war. They are basically against the rest of the world. Unless they can summon food out of nothing, a simple siege could make them die in a miserable, slow way.