So you know that centaurs are the ones with the upper half of a human and the lower half of a horse, and you still think that Asteria is a centaur? Just out of curiosity, where do you think she's hiding all of the horse?
Also, she has horns... because minotaurs are half bull and half human. The original minotaur comes from Greek myth, in which Pasiphae (Minos' wife, hence the "mino" part) had sex with a white bull (Tauros in Greek, hence the "taur" part) sent by Poseidon and gave birth to... the minotaur.
So it's not that you're a dick, it's just that you are wildly misinformed and also apparently don't know what horses look like..?