putting new chucks in with the old chucks isnt what woud personaly do as it is quite a shock to the system for both groups.
its safer for them to have a seperate coop and run for both groups-right next to each other,and after x amount of days allow them to free range together outside of their runs/coops,then the final step will be introducing new chuck into the main run.
its not unusual to see scuffles and chest puffing at the start whilst theyre arguing over their group hierarchy but the new one only needs removing in the adjoined coop/run for space/time out if the aggression is at the point where theyre drawing blood or totaly plucking them.
from personal experience,have found just putting them all in together is to high a risk.
without our knowledge,we had squeaks put into our main coop/run as soon as she was transfered down from our farm by its owner,squeaks was a lovely,friendly but easily bullied hen and henny had set out to prove she totaly owned her,was very uncomfortable with the arrangement and so was everyone else,but after some days,henny had calmed her agressive showboating down and the pair were the best of friends.
keep watching their behavior closely for the time being,but hopefuly these are some fairly chilled out hens.