Your girls aren't neutered though are they Elve? Groups which are neutered are probably calmer together.
I agree - I bonded my two neutered pairs (two of each gender) into a foursome and certainly don't have any scuffles, chasing over food etc, let alone daily. They are all very harmonious and happy, so I would agree with Mandy that your group scuffles and hierachy issues are probably more related to hormones than to the fact that they are a group.