Ok, normally when introducing new members, the new ones need to be quarantined..... Chicks normally get along better with other chicks around same age than with say hens and chicks.... But they are old enough to start forming pecking order... Most people seperate part of the run for about a week so the existing chicks can see and hear the new chicks but can't actually have physical contact with them..... Hiding spaces are essential... I have been told to stay out of squabbles unless one is bleeding,.... I kept my newbies in a dog crate in the coop at night for a few night, they eventually followed big pullets up and roosted fine..... Newbies still get pecked if they step out of line.... But for the most part everyone gets along.... Roosting time comes with squabbles, so if you don't have enough room your prob going to create stress in flock.... If everyone seems to be getting along except for 1 or 2, you can sometimes seperate bully for a day or 2 then add her back in...