I have a catawba-style tractor very similar to yours with 6 standard sized girls in it and they are fine. The footprint of the tractor bottom is 4'x8' and the roosting pole (2"x4") runs 6 feet with a nest box on either end. Even though it states in all the literature that they need 10"-12" per bird on the roost at night- my girls all jamb together on one end with at least half the roost open. Sometimes they all jamb into the nest box too- chickens like to be cozy and I live in San Diego California so it's not because they are cold. Also- they come out into a run (with the tractor in the middle) that is about 22'X10' and scratch/dirtbathe/sunbathe/perch/ snack/dig holes etc. They all go back into the ark of their own accord at dusk where I lift the ladder back up for their safety. I'm sure your girls will do just fine in the set up you have- and it looks great- congratulations
