My coop is 8 by 10. They have a 400 sq ft run, in addition to an acre to free range on. 18 adults and 2 cockerels that are 8 weeks. The little boys are only here till they are big enough for processing. They always have the choice to go outside if they want to. Somedays the weather is too wet and windy and they stay in. Most days, even when it's less than ideal, they go out.
Your birds need more space or you need to get rid of most of them. The longer you wait, the worse the aggression problems will be. And behavioral issues that are caused by overcrowding stress are incredibly difficult to put a stop to, even after ample space is provided.