I don't know if this will help or not as I'm new to raising chicks. But a girl on another site had told me she uses the "playpen" method to introduce new chicks. She basically puts them in the same area ( brooder, box, coop- wherever you have them) but separates them with a wire divider or another small coop or pet carrier. The idea is for them to be able to see each other, but not touch. Then after a few days, she opens the wire just enough for one to get through, but she doesn't force it. They can if they want, but don't have to. Every day or so you open the divider more and more until it's completely open. Also, you can put treats in there, extra roosts, branches, etc. The idea is to keep them busy so they don't pick on the newbie and to give the newbie places to hide if they do pick on her. And a farmer had told her to try and introduce the newbie at night so the others won't notice..but who knows if that actually works. Anyway, good luck to you.