Hey Jugglering,
I dont really think I have that much helpful information for you, as we just let our lot get on with it!
They mostly get on fine, but Sammy and Smokie who are brother and sister, both 4 1/5 years old and the oldest 2 in the house quite often have hissy fits at each other!
I dont know if they are competing, or just dont get on, as Sammy Lee is very much the leader of the house, and Smokie likes to think he is, however he is terrified even if you sneeze or cough and he is in the room!
One little madam we have, Spinks, has recently began to get very defensive of my partner. (I didnt realise cats got so attached to people!) But if she is near him, even sat on the floor, and another cat comes near him, she hisses and bites there ears! But she is a funny little thing anyway!
But we just let them get on with things, we have never had any injuries, and mostly they have learnt the pack hierachy, and everything is ok.