It will depend on how big the Bantams are. The EEs will not usually be too big but the Black Stars can be large compared to bantams.
I think you will be fine but watch for bullying. If one of the bigger breeds becomes a bully, remove it to a temporary cage for a day or so. Do this after they do not need heat of course and you should not have trouble until they are older.
Adding the bully back in will move it down the pecking order so it should not be as aggressive.