Is there a way to give them more space now?
8 youngsters in that space are going to be on each other's nerves. It will escalate.
I know...I have 2 pens about that size (a little bigger) that I lock youngsters up in at night and I also house a couple of adults in one. Closer quarters than I like, but for night security only.
I understand the rain, but if possible, let them roam a bit, provide them with some outdoor space, cover an area with a tarp, etc. I have a hen and chicks that roam when it's lightly raining. Heavy rain they either work their way back to their run or they find shelter under bushes or some other structure.