Provide lots of space, several food and water stations and monitor to assure that pecking is not excessive and causing bleeding. There will be turmoil, but that's part of the social order. Chicken society is frequently like 'mean girls' in high school.
I have a question, our rooster about six months doesn't seem to let our new girls (10@4months) go outside, are they still too little? He lets the two halfies(6months) out. When the little ones try to go outside he scares them back in. What can I do to get them to go out? It is cold here but no enough for them to not be out. We have a heat lamp in the coop and in the covered outside run