We are first time chicken "farmers". Our coop is a converted wooden children's play house. We closed in the porch, made a ramp with closing door. We have a tree limb roost that pulls up to the ceiling so roosting is only done at night. Our chicken tractor is made of 2x4's covered with chicken wire. It is 4' by 8' by 3' high, how many chicken's can use this at one time?