Kind of an off the wall question but long term I'm looking to breed heros or at least collect as many species as I can. I'm picking up some thumb nail size H. notatus today. All else aside (tank size, etc) what is the ideal number to purchase to spread aggression and to down the road get a pair. I ask because I have I've grown out 6 H. efasciatus (from Rapps) for almost a year with no real aggression and I have 4 alleged H. severus curare that are beating the crap out of 1. Is it best to get more numbers or odd numbers or is it just a crap shoot.