Personality plays a big factor. I have six rabbits, five of whom are rescues. I think two of the rescues are sisters, and they hate each other, and would do each other serious damage if given a chance. My two newest adoptees are a girl lop and a boy netherland dwarf. They weren’t a well cemented bond, and were constantly mounting and chasing each other. However, when my other lop, a very laid back boy, was put with them, they both calmed down and are now a happily bonded trio, two boys and a girl, all not related. unfortunately, the girl who was bonded to the boy lop, and was always a bit of a madam, having lived feral for a while is now on her own, as the boy lop made it clear he preferred to be with the two new buns than her. This brings up another point, bunny bonds aren’t always for life, and while you could end up with a happy trio, you need to consider what you would do if either the three way bond did not work, or worked for a while, then the group dynamics changed. Pippi wanted to get away from jenny because she was super grumpy for a few days due to moulting. He insisted on being let in with the new two and now he refuses to go back with her.