I decided to just throw them all together again today and let it play out. Sure enough, the stroppy seven went straight into attack mode, but only on two of them. The other two they left alone. The SLW is top of the pecking order of the wandering foursome, and she was the one who copped it most. The buff leghorn is the bottom of the wandering foursome pecking order and was largely left alone. After about an hour of this, everything settled and they were happy scratching together in the run.
Later, one of my marans hens and the SLW had a bit of a tiff. Kicking at eachother and whatnot. That stopped pretty quickly; I guess they sorted it out in chicken language.
I wanted to see what would happen at roost time tonight so I left them in the run together to see where they'd go. The wandering four are happily roosting with the four I introduced a few months prior: my two araucanas and two marans'. My other nine hens are on their usual roost at the other side of the coop.
Something odd happened on the roost though. There was an egg on the ground underneath the roost (intact), and a broken soft-shelled egg on the roost / all over the BLH's head and neck (she wasn't eating it and was distressed at being covered in yolk). I think the excitement of being with the other birds may have awoken their laying capabilities again and hopefully I'll start seeing some eggs from them.