Brahma drama pullets

Started with 8 buff Orpingtons that lay as of last month. Got 2 Brahma babies raising them all was good until last week they fight and always must be separated. Thought it could be a number issue and got 2 more pullets to offset. This stopped the fighting for exactly 1 day. They freak out when separated so they have to stay close but not together. They have food water the whole 9. Can you help? It’s not like brahmas to do this I thought?!