It depends on the rooster himself I’ve had 1 roo and 6 hens and they did fine, no over mating no missing feathers in the hens nothing. You can have more hens and some roosters will still make some hens bare because they are his favorite or he just is really always ya know “in the mood”. So like I said it really depends on the rooster, for me I’d probably keep at least 8 hens.