Of course every pairing will be different, just like every ham is different. But I'm just going on the general advice that was given to me when I needed it and what also worked/is working for me with both my robo pairs and robo trio.
Often it can all be a bit of trial and error when keeping pairs as some will live peacefully together with a lot more than a single level basic 'pair' set up. Poms robos for example, have platforms, but also the dynamics are different due to the age of the robos being different. I'm sure she will pop up on this at some point.
My trio had a very basic set up while a pecking order was established which involved 3 identical wheels, a big sandbath, open nest and scattered food. After a while I started adding a few more toys, to test how they would cope with it etc. Now, about 6 months later, they have a platform and are still living peacefully, but this could also have easily caused problems. Working out what is right for your specific pairs is a lot of trial and error but the basic 'pair' set up is a good place to start I would say
