Every rooster is an individual. I have had roosters that lived long lives as gentle beings and others that for no obvious reason became aggressive attack birds. We just lost an 8 year old buff rock that was the nicest bird in my flock. I have had New Hampshires and black Minorcas that were really nice and others that would jump you when you went into the yard. The worst tempered rooster I ever remember was a huge barred rock that attacked cars that came onto it's property. Other barred rocks I have known have been real gentlemen. I don't know if there is any way to predict this behavior and I, unfortunately, don't know of any way to manage or stop it once it has begun. We don't eat the roosters so when one does "go bad" it is quite a job finding a proper home for it. I don't know if I have been much help for you but I did have 2 silver grey dorking males and both were very good natured.
