[Sombre]

Regarding caelum - Set some troops guarding your commanders. Spread your mages out a bit more and make sure they are generally surrounded by blocks of troops.

Keep some troops at the back so they are picked up by attack rear orders. Dunno, all this stuff seems obvious so you've probably tried it.

I've never seen Caelum do that. They just suicide against my troops every battle when I fight them. They're just about the easiest nation to beat in SP imo.