I needed to test this with a second cave which took me a while to find but after finally doing so I have to ask: (and I will spoiler this just in case there’s an actual reason for this)
Is it normal for the horrors to fight among themselves?
I spawn them, and back away as I wait for them to spawn. The moment they spawn, they begin in-fighting, leaving just “the winner” to face me - which just needs a .223 to the face to kill him - even though at “|…” health I could probably sneeze at them and win.