Now I'm wondering if I was overreacting about the aggression between them? Without any frame of reference it's just so difficult. There are lots of opinions online but no structured reports/science. The divider didn't arrive in time before we went away. On return they both are still alive, the skin patches I was worried about before are gone (I've read they can suffer skin complaints and go down hill quickly so I always try to get a good look at them every day), and they are no longer sleeping in the same spot but seem to spend most of their sleeping time at separate ends.
Thinking perhaps what I witnessed was them moving from juveniles to teenagers and them stropping that they need their own space now?
Oddly I'm now more concerned about the larger one, the previous aggressor, as he has a small white spot on his nose. He also isn't as forward at feeding time. He's also the one that's moved out of the original nesting spot. Perhaps he just needs time to settle. What's the best approach for the nose spot?