I have one girl in the middle of two boys--she and G have had a few little squabbles where she backed off and screamed, and her and Roman get to chest bumping in play and she gives him a mouthful. Even though Roman is much, much larger. Most of the time she is super sweet and leading the way on walks. So in my case, if I was to get another girl, it would need to be a more submissive girl, because Fuzzy is definitely the Queen.
And it can be a bit of challenge to get two to go up stairs, when one is balking! Practice makes perfect!