here's a coop design question for y'all -- i'm thinking of expanding my coop -- it currently is an 8x4' henhouse inside an 8x12' run. easiest thing is to add on to one side, so that it might become 8x20' (adding another 8 feet) or some such number. but here's my question: what are the pros and cons of making it one huge space (so that there would be a single flock all mixed together), or two (or three?) separate spaces?
here are a few photos of the existing coop/run:

when first built -- there's a fairly large/flat area to the left of this photo, which is where i'd likely put the expansion.

another photo of the henhouse side, after adding external nesting boxes -- this is the side i'd probably add on to. if making it all one big space, we'd just take the wire netting off of the section below the henhouse -- or could leave it on to make two separate spaces.
the way i see it, the pro of separate spaces is having the ability to separate a few birds for breeding, or making it easier to introduce new birds to the flock while keeping them separate for a while -- but the pro of a single space is the flock would feel less crowded (i have 12 adults now, and 11 chicks growing up, some of whom will be boys and probably won't stay -- but given the reality of chicken math, those numbers could, ahem, increase), and then they could all free-range together when i'm home (as they do now) & not have fights?
i guess that's a related question -- if chickens live in separate coops but all free range in the same yard, do they have fights, or do they just stick to their own flock? would i have to free-range them separately?
thanks in advance for any thoughts or suggestions!
here are a few photos of the existing coop/run:
when first built -- there's a fairly large/flat area to the left of this photo, which is where i'd likely put the expansion.
another photo of the henhouse side, after adding external nesting boxes -- this is the side i'd probably add on to. if making it all one big space, we'd just take the wire netting off of the section below the henhouse -- or could leave it on to make two separate spaces.
the way i see it, the pro of separate spaces is having the ability to separate a few birds for breeding, or making it easier to introduce new birds to the flock while keeping them separate for a while -- but the pro of a single space is the flock would feel less crowded (i have 12 adults now, and 11 chicks growing up, some of whom will be boys and probably won't stay -- but given the reality of chicken math, those numbers could, ahem, increase), and then they could all free-range together when i'm home (as they do now) & not have fights?
i guess that's a related question -- if chickens live in separate coops but all free range in the same yard, do they have fights, or do they just stick to their own flock? would i have to free-range them separately?
thanks in advance for any thoughts or suggestions!