Pre-fabs always violently over estimate the number of birds a coop can house. You can physically stuff them in there but that isn't what is best for the birds. The coop is also severely lacking in ventilation. They are very cheaply made and don't hold up to the weather.
Chickens do best with at least 3.5 sq ft (4 is better) of coop space, 1 linear foot of roost space (at least 1 horizontal foot away from the wall and other roosts) and as close to 1 sq ft permanently open ventilation per bird in the coop. You only need 1 nest box per 4-5 hens. So you can see looking at that dinky pre-fab that numbers are not adding up.
The chickens also need 15 sq ft of run space if they are to be confined vs. free ranged and you need to have an area that is protected from the weather to keep food dry.
