Would be advantageous for integration...especially if you brood the chicks in the small coop and have an opening between the 2 runs.
https://www.backyardchickens.com/articles/integrating-new-birds-at-4-weeks-old.72603/
My integration plan Was to brood the new chicks in the existing coop with 3 out of 6 current hens and a panic room style hardware cloth wall, and move 3 retired hens (in their last summer of laying before freezer camp in October) would be in the new coop. That way I don’t over populate either coop.
What you may be suggesting
@aart is that the new chicks be raised in the new small coop and the 6 existing hens stay in their coop. At some point (3 Weeks) I open doors
For panic room style integration in the runs. I guess my concern with this is that I feel the older hens will have an easier time of splitting into two flocks of 3 and adding the chicks to one all in one go, rather than go from a 6 chicken flock, then to a 9 chicken flock, then back to a 6 and a 3 (because at some point I need to keep them separate 3 in one coop/run and 6 in the other, to avoid over crowding issues).
I was going to treat the new 3 hen set up as my “retirement home” for my 3 oldest hens. They already know how to roost and lay in nest boxes and use a coop ramp, so they will be the most adaptable to throwing in a different coop. I wanted the new chicks to observe these behaviors in the bigger coop from the 3 older (1 year) hens they live with.
Am I just way over thinking this?
Oh second thought - the new coop is not
Going to be as winterized, eg no water heater lightbulb Setup and probably not as concerned about drafty wind conditions because I only plan on using it May through October for fully grown hens. They will go to freezer camp in October and the new oldest ladies move in when new chicks arrive at the big coop the following spring.