Rescues not assimilating.

We adopted a couple of rescues a few months back. Took a week or two to settle in, stretch the legs/ wings & figure out where home is (they have a separate chook tractor maybe 30 meters away. So since we've introduced them to "the flock", they've been argy bargy & asserting authority. Our resident mob are terrified of them especially the 13 year old australaub who is "in retirement". They free-range together but still at a distance, & with agro, after 3 months. Understandable after being a barn layer for 3 years I guess. Anyone else been through this I wonder. Solutions? Apart from locking them all in the main coupe & watching the carnage? Never happened with the breeder chooks introduced over the decades. Cheers from downunder.