Idk what to say for sure then Angiebubs... ours are free range. And that has worked so far for me. They are integrated at about a week. As soon as they seem strong enough to get up and down our coop steps with mom. Because I water outside. Although, our flock has newbies constantly added. And our top rooster Rae never allows one to pick on another. Even our duck Quack from Terri attacks the turkey hens when they try to pick on the broodies. Bbp, I think it is a turkey thing... I think we are very lucky to have those two here. They keep things peaceful.
Angiebubs, maybe it is best to add one group at a time. When I add young chicks without a broody, I always do it when I will be home for an entire day so I can keep tabs. But I also have a pen outdoors that only chicks can fit into. I provide chick feed and water in their safe area. They learn to follow the teenagers there. Is there a way you can provide a spot for the broodies to send their chicks?