I agree. Pullets are costly. I prefer to raise and then integrate. When I do integrate, I keep them real busy with stuff to eat, places to run to and water to drink. They'll have to sort most of it out for themselves but I keep an eye on them. I just integrated a new flock of 15 into an old flock of 6. Having more "new" chickens helped. The smaller, established flock gave them all the typical stink eye reception but once they started going after a couple of heads of cabbage, scratch, spaghetti, etc., things settled down. Roosting that first night was interesting and you could hear the fluttering well after dark as they all competed for space. I lost one the first night. She flew over a small snow fence that I was using to keep them in one general area. My wife tried to run her down (you know, you can never real run a chicken down that doesn't want to be caught) and a fox got her that night. After a couple of days, they were all OK and free-range just fine now.
I had a fox problem all winter and spring. I finally tried one of those flashing red "eyes" that is recharged by solar power. We still see the fox but never in front of the coop any more. Usually running across the garden or near an out building. That doesn't mean it stopped coming close up to the coop but I feel better lately. I move the "eye" to a slightly different location about every two or three weeks just to keep things mixed up a little.