That's a good idea. I'll do that on the weekend when I know I'll be there to watch them at dusk.Close off the smallest mini coop one morning as soon as they are out of it for the day and see what happens at bed time.
I'm definitely seeing that raised-together grouping happening. That's one reason I'd like to get my three hatchlings roosting with the older gals. I've got one very friendly pullet and two cockerels in that group and the boys are going to have to go to new homes in another month or so. I'm worried that my little gal is going to be without a friend, since my other group of youngsters (who were in the brooder box together) constantly chase her away and she mainly hangs out with her brothers.