Good job in re-inventing the chicken tractor. Honestly, I believe the scale and the shape are just secondary aspects. What's important is that you manage your land by giving access to the chickens in certain places, while restricting them in others. My favorite part: you break even in the end. Sure, you have to buy feed and straw and things, but by selling eggs and hatchlings you make up for that. (Everything you eat in forms of eggs, veggies, or even meat is on top of that.)