@ Latestarter-Separation is not quarantine, you can not do quarantine and integration at the same time. It was confusing in your post.
I am unclear as to the age of the new birds. Age, size, and space makes a difference too. One old bird plus chicks, you need separation, and a safety zone where the chicks can get away. Not yet laying hens, will be a little lower in the pecking order.
Chickens hate change, the more change you do at once, is better. What you are proposing, might work, but might be a wreck for one or two birds. You need to have a separation option, a see but no peck for at least two birds. Time will tell which birds.
Good luck