JacinLarkwell - did you raise those birds together, or were they all strangers to each other when you put them together?
I think that the fact that the op is new to chickens, putting strange chickens together, that the size difference may cause trouble. However, I do not have experience with...
Another trick that might help, is to make sure there is a lot of clutter in your run. Many people just have an open space, but hideouts, roosts, platforms that birds can get on or under, places to eat out of the sight of other birds eating at a different dish, can also help.
My question is, how old is your son? If he is under 6 years old, I would be very wary. Small children can take an attack in the face, and children are usually the first victim of a rooster attack.
I personally think roosters take a bit more experience than hens do. Roosters have ruined the...