Questions about letting mama hens raise babies instead of using brooder

I had my broody hen set up just like that in a dog crate. But I only had 1 hen. My crate was sitting inside of my large coop with my other chickens. I tried to use a thin piece of plywood about a foot tall around the inside of the crate to keep everyone inside.  But they pulled it down about a week later and nobody paid much attention to the babies hopping in and out of the crate. I opened the crate door when the babies were about 10 days old because the mother hen was having a fit when her babies would hop out and she couldn't get to them.  The mother hen took care of anybody that got to close to her babies.She was enough warmth for them and I didn't need to provide any additional heat.  I would remove the divider and just let the hens be together.  After the babies are born I'd move them all into the tractor when they are a few days old and up and moving around. And I'd open the tractor door immediately.  The mother's will know when to take the babies in and out.  My mother hen is eating the chick starter feed. I am also giving her a treats and scraps and she makes sure the babies try everything I give her.  I would put the tractor as close as possible to your other chickens, maybe inside their run?  You really only need to provide food and water ~~ the mother hens will take care of EVERYTHING else!!

I never thought about hens wanting to sit inside same box.  Yes, I would wait until they are hatched and then remove the divider.  They will probably all cram inside one of your nest boxes, so you will probably be able to remove one box then. They may fuss a little at first until everyone sorts out their chicks.  As long as you have hay or shavings inside the tractor house you can just add the chicks and their mothers when they are a couple of days old.  They will snuggle up under their mothers down in the bedding and be warm. Yes, I would definitely put the tractor up next to your other chickens. Everyone will be curious and checking them out and they will be familiar with each other when they are all finally added together.  I did 10 mail order chicks like this and there were no issues at all when I put everyone together in the big coop at about 6 weeks.