Now that is an interesting question. I've been chatting to my Finnish friend about just this. He has both free range and contained. He's involved in a repopulating endangered breeds project.
He tells me that free range birds have more disputes. He reasons that it doesn't take an intelligent bird long to realise that the consequence of aggression can't be escaped from. If half your options are shut off; fight or flight, then one may be a bit more careful about behavior.

This makes a lot of sense to me and chickens, being the masters of adaptation and social living, are I would have thought, likely to come to an arrangement. There is no pecking order in jungle fowl and feral flocks I'm led to believe. It's an adaptation to keeping circumstances.