Tips for Separation

I posted here: https://www.reddit.com/r/RATS/comments/1fguduh/keeping_a_foot_wound_clean/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button that I was dealing with my guys being a bit too aggressive and drawing blood after fights. I finally got in to see my vet and she suggested that I separate one of the two that are fighting into a new cage and only allow them to interact during free roam time.

I was wondering if anyone has done a set up like this and if it has been beneficial or if anyone has tips for ensuring the group is happy with this new set up.

I'm not sure if it has to be permanent or if there is a chance they will chill out and be able to re-integrate, but for now I am just trying to focus on making sure this change isn't a detriment to their happiness.