Roosters DO have occasional conflicts on range, but they are normally very brief.

How to Raise Chickens, see my entire video here: https://youtu.be/msko6-fbLoE
So many people comment on how harmonious my ranging flocks are. "How do you keep roosters from fighting?" is a very common question.
Well, truth is, I don't keep them from fighting... it's a normal part of their territorial and peck order process. Separating roosters that you intend to keep, only puts off the normal hashing out of who is going to have what status among roosters.
They need their spurs and beaks for normal personal defense and for challenging predators such as hawks and feral cats among others.
In this video short, the buff/orange colored rooster has been the frequent challenger with this Brahma. At the very end, a Blue Andalusian Rooster keeps the peace by breaking them up.
As a note on Rooster aggression, NEVER EVER keep a rooster that shows aggression towards people... they CAN do harm, especially to children. We breed for temperament as well as good looks.
Their spurs can get quite long and sharp. 10 years ago, one of our sons was spurred right through his tennis shoe... he doesn't like chickens to this day.
Careful observation is key in protecting flock mates from harm as well as keeping your visitors young and old, from having a bad experience.

So, "how do they all get along so well", at times, they don't... this video demonstrates that clearly.
Want to learn MORE about chickens? Please click this link: http://www.amazon.com/Regarding-Chickens-Incubation-Hatching-Brooding/dp/B000K28MI0/ref=sr_1_1?ie=UTF8&qid=1427496718&sr=8-1&keywords=Regarding+Chickens