I would put the big girls out and lock them out, and put the little girls in their space. Lets them explore in safety. Lets the big girls see them in their territory. After a while, go down and chase the little ones a bit so they can find some safe places.
Or you can let the little ones out to free range, keeping the big girls in their run for a while. Let the new ones explore with out being chased, get their bearings, find some safe places, then an hour or two before dark, let the big ones out.
It really doesn't probably matter, but it seems to me that people get into a wreck putting new birds in a strange place with strange birds. Not only are they being attacked, they don't have a clue where to go to hide.
Works for me.
Mrs K