Enemies won't move or jump to the correct position to shove you off a ledge so it can be exploited easily.
When they do... yeah it might not be the best combat design when someone insta-kills you with a shove or a knockback arrow (what is this nonsense anyway?). Odd thing, the characters who fall into a bottomless pit or the bottom of an underground sea somehow turn up at camp.
But I agree, the AI should be taught all the same cheese the players get to use. Always backstab with advantage. Always attempt to shove off a cliff. Always eat a pigs head for +12 HP. Use arrows and bombs from other enemies' inventories. Use stealth right outside players' visibility cones.
Or.. I don't know.. get rid of the cheese entirely?