Three to five females per male is the recommendation for coturnix quail, which are flock birds. Button quail aren't flock birds. If you put a bunch of them in a big enclosure, they tend to pair off, like bobwhite quail. If you get lucky, you might find a group of more than two that gets along, but they can seriously injure or kill each other if they don't get along or if their opinions of each other change. It's not worth the risk.
If the female has space and hiding places to avoid the male, they'll be fine in just a pair.
The breeder is potentially focusing on profit rather than the animals' welfare. How do you know there are no problems? Have you sat and watched the birds for long periods of time to be sure? I wouldn't put three pairs of buttons in anything less than triple that space, with a lot of cover and escape routes.