I have stopped raising roosters or meat chickens in the backyard so my answer is based on surplus pullets. The last cockerel that sneaked into the batch of pullets was re-homed as soon as I knew that he was out there. I think it was about 8 weeks.
It looks like you have dual purpose breeds for the most part. They won't grow anywhere near as fast as the Cornish X that is usually kept for meat production. I say "kept" but being around for 7 or 8 weeks isn't much "keeping."
Extra pullets here stay for about 15 or 16 weeks so they've got twice as long a run as the Cornish X I've had. They don't eat feed nearly as fast so they aren't a heck of a lot more expensive, if at all.
I wouldn't keep roosters a day longer than they are tolerable to have around, however. Whenever that magic switch is thrown that sets them off fighting for breeding rights - they would go off to "freezer camp" if they were in my backyard. Any feed conversion to weight gain is going to be very poor from that point on.
Steve