Only towards the end, a hero with a mediocre army appeared, but he got a little bit of damage and ran away.
Added 5 minutes later
Yeah, they love doing that. Right now, I'm playing as Arantir in Lords of the Realm on the 5th map, and the AI just keeps running away. Moreover, the demons, which seem to be scripted to do so, always attack me regardless of the size of our armies and never run away, but the heroes of the Order faction run away after just one or two rounds.
He didn't have any Chaos spells this time. Somewhere, a witch gave him Summoning, which he doesn't really need, except maybe for Phantom. And also Darkness.