This nicely exposes how ridiculous it is that centaurs have a 3rd set of limbs: the human arms.
Terrestrial mammals have 4 limbs. Even bats have 4 limbs. Only aquatic mammals like whales, dolphins and manatees have lost their hind limbs.
6 limbs is an insect.
Having said that, I do appreciate centaurs because it's at least more distinct from "boring human" than virtually every form of forehead-applique alien common in most science fiction.