I agree with your statements for the most part. Space for each flock to spread out without running over another flock's toes is essential to freeranging several flocks together.
We have 248 acres and the chickens range by choice on about an acre around the house, barn, garden and the flock pens. I have over 100 birds in the combined flocks. Maintaining peace means knowing which roosters can be gentlemen outside their pens. The hens usually get along nicely. I enjoy spending time out with the birds and they follow me in the garden waiting for me uncover grubs etc.
This photo has the layer flock with some of the breeders out and about between the barn and garden.
Yes the two older hens in the lower right are a little feather bare in the picture...they have since grown those fethers back in.
If that's working for you, that's awesome.