It's adorable! :love
But its too small for 5 chickens. Also, having 3-4 hens to one rooster is hard on the hens.
People who design coops don't have chickens, they're trying to sell a product, so they make them cute, not practical.
If you doubled the length of the run, you could get away with 5...
Plymouth Rock is the breed, Barred is the color, yes, that's what they are. The big one is a rooster so he's not going to give you a single egg. you might want to build a bigger coop, that one is a little cramped.