Bryam,
Dont get discouraged by some of the posts you see on BYC, what you want to do is fine and probably better for the little hens anyway. You're not going to alter the universe or kill off the entire button quail species by putting a trio of hens with one male. Yes, in the wild buttons are monogamous, just like most quail and most birds for that matter, but in the wild a hen can simply fly away if her mate gets rough with her, in a confined cage she cannot. Male buttons are very very aggressive during mating season, just like any quail and will stress or even kill a single hen with his aggression. Hence the reason, most quail breeders that keep quail in captivity do trio's. What you want to do is fine, and hey, if the male decides to mate with just one of the hens like they do in the wild, that's fine too, but they're not in the wild and I guarantee you that lil male will keep 2 or 3 hens busy.