Hello everyone, following up with an update and question. The two silkie mixes have been integrated with the 4 older hens for almost 3 weeks. We doubled the run from 4x10 to 8x10, as well as added a second door from the coop to the run, so no more bottle neck issue. Things go quite well during the day. The two silkies will occasionally get pecked as they go by an older hen, but this is minimal and most of the day they coexist peacefully. The eat and drink and free range like normal hens. 
The issue we’re having is in the coop at bedtime.  The following descriptions come from me observing the camera in the coop. The silkies have learned they need to wait for all thek older hens to get settled in their spots before enLtering the coop. If they come in too early, an older hen will jump down and chase them out. Eventually, the silkies will jump up, find a spot, settle in, and all is good. This would be a “good night”. We’ve had maybe 2 good nights in 3 weeks. What usually happens is that Montana, the head hen, will shift her spot in the roosting order and sit next to the silkies and peck, peck, peck at them until they jump down. In the process of Montana shifting her spot, the other 3 hens then get up and shift their spots to be next to her. (We have a cross-shape roost bar set up.) the silkies will jump up as far away as possible from Montana and this usually means they’re near the Polish hen, the lowest hen on the pecking order, who leaves the silkies completely alone. This peck, peck, peck (sometimes for 2 minutes before the second silkie finally gives in and jumps down) and hen shifting spots routine is how most nights have gone in the last few weeks. The last two nights however, the silkie that is left (one usually jumps down pretty quick once Montana starts pecking), has “stood her ground” and not moved. Montana pecked for over 3 minutes, was quiet, pecked again, was quiet, pecked again, etc over about 10 mins. Eventually everyone slept and the lone silkie slept next to Montana all night. The last two nights we’ve not been home to help assist in the bedtime routine (aka watch it on camera) , otherwise I would have intervened and moved the lone silkie away from the constant pecking. 
My questions are: 
1. If a sub-hen is getting picked repeatedly, why in the world wouldn’t they jump down/move away? She had room. She wasn’t stuck. Was she making a point? I don’t get it. 
2. Is there anything I can do to make the coop integration go easier? Mix up the roosting bars? Make sure I never miss bedtime supervision for the foreseeable future? Intervene like I have occasionally? Let them be completely? Sequester Montana in a dog crate overnight for a couple nights? What do I do/not do? 
My friend pointed out: if we didn’t have cameras, we’d have no idea any of this scuffle was happening. There is no bleeding, no bald patches. The silkies aren’t hiding in the coop all day or cowering away from the older hens when out in the run. So is this bullying or just normal integrative woes? 
I’m happy to post a video link if it’d help to see it, but I hope my description above was enough to convey what’s going on.