If you don't know the dimensions, how can you be sure it's got plenty of room for 10? Your idea of plenty of room may be very different than what your chickens think is enough room. On average, to prevent over crowding stress, you need about 4 sq ft of coop space per bird and 10 sq ft of run space per bird. For 10 adults, you would need a minimum of 40 sq ft of coop space and 100 sq feet of run space.
Effects of free-ranging vs. confinement - Page 2
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Many people hope that free ranging will let them keep more chickens than they have space for in the set up. And it will in the summer, kind of sort of. In the summer, most of the 24 hours is daylight, and the birds are mostly outside. However in the winter, at least in the northern hemisphere, most of the 24 hours is dark and they spend the time cooped up. Mine are generally headed to the roost by 4:00pm and not coming off until very close to 7:00am. Those are the times that free ranging will have no real affect on the temperament of the birds. The space inside the coop is the limiting factor. They will fight to be in the coop.
As mentioned, and you are aware, you have too many roos. However, I would also like to point out, that part of your flock is not full grown either. As they reach full size, they take up more room.