Hmm, that makes me think. Some of us think "Them/They" are aliens. But yes, I agree, they did look a lot like poes, even look at the practice balloons! Anyway, as I was saying, "They" could be poes and poes are ghost like enemies, correct? Hehe, funny. Alien-ghosts.Romani never uses the word "aliens".
She only refers to them as "them" or "they".
Even though the method they use to abduct cows is very alien-ish, we can assume that they are poes.