How much sq ft is that? Exact run and coop measurements would help. Just eyeballing it it's too small for the number of birds especially during integration (Can't tell if the part behind there open? There's a blue structure in back and some mulch but not sure if that's part of the same run space or not?) Space related stress is a top reason for aggression issues.
There's also no real clutter for the younger birds to take cover behind. Clutter eats up space, which is why having more than minimum space is important especially while integrating.
Pinless peepers to me should be a last resort. It's not a magic fix. Improve the layout and space and maybe add in the peepers as well, and that should help ease some of the tension in there.
Also put all the birds on the same feed - as there's no way to stop the younger birds from eating layer, they should all be on all flock or grower. Provide oyster shell on the side for the hen.