No Coop No Problem
Songster
This is good advice. There's a lot of places in this world where people are comfortable with one another only because they can't see one another- because of walls, trees, fences, etc. However if those visual blockades weren't there then conflict would happenThe size looks good! I definitely think with lots more clutter they'll feel more secure and won't pick on each other as much. If you have any lawn chairs you don't use, dog crates/houses, buckets, large pots, branches, ladders/step stools, stuff like that, use them! They can be used to escape under and behind and on, but also to hide enrichment items, food and water.
I personally have around 50 chickens of all ages outside right now and they're not violent with one another. There's no chasing, feather pulling, fighting or injuring each other at all. Violence is not natural behavior for chickens other than mature males competing over resources. It sounds like your chickens are having stress-induced behavioral issues