My families seem to sort themselves out, I have a trio of two ganders to one female but that is there choice of about 30 others , a couple of one of each pairs and other groups of four or five. As said, they have sorted themselves out and have a good choice on free range. But saying that I have a loner that hangs with the ducks. I would just watch and let themselves sort out who's top goose and see if they get on then, you dont want to be without a gander if something happens to one of them over winter and with breeding next year.