When is it too much?

I just got a rooster on Saturday in hopes my girls would stop being lil dickheads to each other, but currently all they do is chase said new rooster into a corner and just straight up pin him (and usually peck him at least once and once and a while take a single feather along with them). Should I be separating him now into like a dog crate like I've seen some people say to do, or should I just keep letting this happen (since I did see this is also a somewhat normal thing and can take a while to stop). The hens are currently 7 months old and according to the person I got him from he's currently 6 months old. I haven't found any blood on him, he's just quite spooked with them and his current predicament.