Here is my two cents and what I have found I have two barred rock roos and one silkie roo. All three roos were added later after my established hens. The destroy my first hens. Now the barred rocks have one sister that they grew up with, and my silkie had one sister he grew up with. While they breed with there sisters, they are not as rough with their sisters as they are with my other hens. My silkie and his sister have to live alone, and my barred rock roos will be getting their own coop. If they all have been together since chicks you may not have a problem. My BR roos fight, but usually only over the girls. This has just been my experience and obviously it may not be the same for you. So you may not ever have problems, or you might depending on how aggressive they are with each other.