Does that not speak more of the differences between centaur and human than DD and anything else
Also, how are you getting 1500? You don't have Psionic Lion's Charge unless you're doing something really weird, so you're trying to do that all in a single attack?
And unless that +6 strength is really doing the bulk of that extra damage, that amount of damage would have killed anyone anyway. It doesn't really matter whether you're doing three hundred or three million; they're just as dead.