I would not get more than one Male. Males tend to bit at females when time to mate and you dont want compitition in the tank. two females and one male is the only way to go if you are trying to breed them. I have 8 total. and never put more than one males in a tank with any of my females. I have only been able to get one to breed in cap. she had two... was cool. but .........
if you decided to breed, when you find out she is preg. Make sure you pull her and keep her in her own tank. No tank mates, male or female what so ever..