Currently, we have a great deal of animals that do melee attacks, but not ranged attacks. This idea combines both – melee attacks but from flying animals, swooping in for an attack. Against melee ground opponents, all one has to do is climb (even just hang on the side of a cliff) for the animal to go away.
But what about changing that ‘always works’ dynamic? What about adding flying birds as enemies to the map? I’m not thinking of a single Eagle or even a few vultures to swoop down on unsuspecting players, but a whole flock of birds like black crows or vampire finches. Something similar to Alfred Hitchcock’s Birds (1963).
Open air bases might be a problem (unless that base have some efficient archer thralls guarding it).
Just a thought about adding some new threat to the game. It may not work due to game engine limitations.