Welcome to BYC!I just got a new rooster & put him on the roost with my 7 "roosterless" hens. Checked them in the morning, and they are taking turns pecking at him. He won't fight back, just cowering in any corner he can find, like a wimp! Is there any hope for this rooster to intermingle and do his roostering?
How old are all the birds involved?
I'm betting your 'rooster' is a cockerel yet (under one year old), immature and maybe even less than 5-6 months old.
Most any new bird (except a full grown mature cockbird) thrown into a flock will be harassed.
Read up on integration..... BYC advanced search>titles only>integration
This is good place to start reading:
https://www.backyardchickens.com/a/adding-to-your-flock