I currently have 9 chicks that range in age from 4 to 6 weeks old. I think I have 4 roosters, but we are going to wait another week or 2 to be certain. The lady who I got them from will take back and rehome the roosters. She has others chicks available. How difficult would it be to introduce new chicks around the same age as my current chicks? Could I possibly be a long integration process or not really because they are the same age?