I think it probably does have to do with the particular breed personality to some degree.
And,
@hoosiercheetah , the owner of this forum has a book out that he co-authored with a vet called, "Chicken Health for Dummies". In his book, he encourages an
"all in all out" policy like you're talking about for many reasons.
I really struggle with that for a couple of reasons. One is that I'd like to be "self-sufficient" as much as possible so I'd like to have my flock begin raising their own young and not be as dependent on an outside source for chicks. Another is that I am hoping to see them be a more "natural" flock in which there are chickens of all ages.
The other side of that story is that in nature, eventually there would be sub-flocks that would form and go off into another area to continue to proliferate which would happen over and over with an unlimited natural setting..... Which we don't have in captivity unless we just let them take over all the acreage and live all over the place instead of cooping.
Sigh.
So...all of this is to say that I'm still in process trying to figure out how I want to handle it all myself. I know what my "idealistic" self would like to see. And I definitely appreciate the reasoning behind "all in all out".
I think, in the end, if I continue having chickens I'll end up somewhere in the middle. But we shall see...based on my experiences and the time and the resources I have I'll have to figure out what works here. Either way, I hope to emulate the most natural situation I can in husbandry.