What am I doing wrong? What do I need to change?

[CabritaChicks]

Well…for now…until you get more chickens…

Brilliant! (it happens, over and over again, even when you don't expect it).

 

[KyCoop]

I call the night time roosting routine the thunder dome. My girls have been together for years and there are still nights they squabble and hair pulling over spots.
Let everyone put themselves to bed they will work it out. The more you intervene the longer it will take for them to figure it out.
The older girls will go in before the young ones and roost up. Then the Littles will learn where the big girls like to roost and won't be taking someone's spot.