Not sure where you are getting your info from. Ackies will rarely fight. When you introduce new individuals there will sometimes be a bit of a squable with nothing worse that superficial wounds for dominance but rarely ever a full out battle resulting in any serious injury... They certainly do not need to be raised with eachother in order for them to co-exist in a housing unit. I constantly bring new blood into my breeding groups without any serious altercation.
They are also quite easy to sex. Their heads and tail bases are differend and like most Australian dwarf varanids, they have raised scalation on either side of the vent. The scales are different between males and females.