I bonded a female with a male/female pair. The scraps were between the girls and never drew blood! The male, Floppy, used to try and keep the peace.
Unfortunately one of the females was extremely ill and they were only a trio for a couple of months.
I am actually now in favour of trying larger groups. This was the second time Floppy lost his partner, the first was his brother. He seemed to cope more easily when Mittens died because Millie was still there.
I am hoping to adopt Starfish from Honeybunny and will try and bond her with my pair. They will hopefully go to the rescue I foster for to bond this time.