It will probably depend on your chickens if you get to many Roos your bound to have some fights, they may not divide and go in the right coops .. If you are going to try to keep breeds pure for the future then it could be cool just to have a divider in the runs then they can socialize with out over crowding .. I love your idea .. If it were me I would connect them like you were saying but put chicken wire in between dividing some areas. as then you could keep smaller new additions in one.. and divide them to your choosing .. If you Dont intend to have any Roosters or even only one and same size aprox same age chickens then I think you could def use an open runner.. but they may not go to bed in the coop you had in mind : )
