I have fenced off about 30" square in the main run. Converted an apex into two room hen house, insulated against the cold nights we are having now. I used a fine mesh and doubled it over, as they tend to fight through the fence. This just stops any physical contact but allows them to interact...
Doing really well. Had to separate the bully's for a few days but they have rejoined and all seems better. The light Sussex are so tame, I love em. And with more characters it's hard to know who to watch!