I have 10 females, 9 standards & 1 banty. Here's my situation:
3 adult hens who are over a year old (BSL, RIR, banty cochin)
2 "tweens" who are nearly full grown & about 3 1/2 months old (BO, BA)
5 chicks who are just over 2 months old (BR, BA, 2 crested polish, 1 standard cochin)
My girls have been sleeping in the coop together now since about the end of April for the tweens, and the babies got moved into the coop in the end of May. The youngest 7 pullets have always gotten along, despite the age difference. We just put them in the yard together and there were no issues.
That said, we have to keep the adults separated from the younger birds unless we're supervising. The coop is divided in 2 sections so that the girls can all see each other, or even peck through the wire a bit, but the adults can't get at the younger birds. This has been important because the adults have beaten the crap out of the youngsters several times. The poor buff orp has had her behind handed to her at least twice, with broken skin and bloody wounds being the result. One time she even escaped to the neighbors yard - complete with 2 dogs - just to get away from the beating (thank goodness for fast-acting neighbors who have a rabbit hutch).
We're working on integrating the younger birds with the older ones very slowly. They've been near each other now for at least 2 months. They can see each other, they sleep together, and the beatings continue. The younger birds are too young and/or too docile to stand up for themselves. They will, in time.
So no, I'm not a believer in the "wake up & be friends" approach. Death by pecking is not an option in my backyard flock.