I had 2 mother daughter tandems inb seperate hutches, when one was alone I gave them to opurtunity to meet up in the big garden, when I saw them hanging out together I connected the hutches with a tunnel. Did work fine.
Usually I have 4 does, don't have scabs or fights. Some humping now and then, but that's it. I think a structured space helps where they can claim one part or get out of each others eyes when they feel like it.
Bucks, no idea. If I want all bred he can spend the day in the garden with them for three weeks, otherwise he has his seperate hutch. Never tried something with multiple bucks.