While watching the opponent's turn, I noticed that the AI-controlled Goshan was cheating. :D He flew over the orcs (meaning he exited the ground and entered the dungeon via a lift) and attacked the boars. How is that possible?! If you look closely, you can see the spirits of the former boars. )))
P.S. After the game, I loaded the save (thinking maybe he stole a scroll or got free wings, but there was neither). He bypassed the guard at the top of the lift.
Check out the physics; the order of attacks by neutral creatures on an adventure map is always left to right.