As long as you have at least a foot of nicely sized roost length for each bird, it's just a pecking order thing.
My flock that have been integrated for 4 months now, have a 'pecking party' almost every night at roost time....nothing to worry about unless someone is being bloodied.
All flocks...
Ditto on the lack of space...also feathers usually won't grow back until a molt unless they are fully 'plucked' out and not just bitten off, and all 'solutions' take time measured in weeks to bring results.