I haven't found Protection and Aggression to be connected.
Being aggressive towards hens and chicks and being aggressive to humans seem to me to be a lack of intelligence - they misidentify targets.
For a few hours this afternoon I was lounging around in a chair in the backyard with the babies playing around me and our most docile, gentle rooster Clifford under foot keeping watch over them. He doesn't let the hens pick on them, does a body block thing. It works because he's huge. He's also got wicked long curved spurs. But he never gives me a mean eye or pose, so I can totally relax out with his flock.
Yet it was only two weeks ago when he got himself covered with the blood of his enemy, a feral roo. And he's always watching the sky or the woods to keep everyone safe.
*With our 4 other roosters I don't relax this much, but none have ever challenged any humans. That's why they got to stay and enjoy having hens.
Every cockerel that got a mean eye has been removed before they attacked, and some were terribly neglectful of protection / lookout duties.
There are tons of nice roosters out there looking for a home. People show them mercy because they're nice. I'd really like to encourage you to go find one.
Like my mom taught me,
Never settle for aholes