I have a similar issue. 10 six week old pullets and 10 one yr old hens. They've been together since the pullets were 2weeks. Integrated fully during the day since week 4. They still sleep separately in the coop.
Only one hen is causing an issue. She rips patches of feathers off of the pullets of she can grab them. No blood. She pursues them if she's up and about and they are in her view. She does give up after about 30 seconds maybe???
They all have access to all those areas all day. Pics attached.Do I need to change anything or separate that hen or just stop worrying?

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