Question about sleeping, roosting and pecking order

I have 7 pullets and a 5 foot long roost. There is plenty of room for all of them to sleep along the roost but they all cram together at one end, which is super cute. The thing is two of the girls (a cochin and a salmon faverolle) are sleeping on the poop board underneath the other girls who are on the roost. The girls on the roost are only taking up about 2 to 2 1/2 feet of roost but if the cochin or the SF try to get onto the roost the other girls won't let them. They could sleep on the other end together but they seem to want to sleep with the flock, even if they have to do it on the poop board.

I have only had them all for about a week and a half. Will it always be like this or will the cochin and SF eventually be able to get on the roost?

Thanks,
CJ