I'm sorry but you don't have a mature rooster and mature hens, you have an immature cockerel and immature pullets. There can be a world of difference in the behaviors of mature adults and immature juveniles. He is probably just hitting puberty, a little young but some do that. He wants to...
How old are they, male and females? What is actually going on? "They freak out" isn't much of a description. What does he do and what do they do?
Typically when a mature rooster is introduced to a flock of mature hens he mates couple and it's over, they are his flock. He wins them over by...