In my experience, 'normal' is whatever the breeder of the last few generations of ancestors of that bird believed it was. If they believed violence was normal --- it will be, at least in their stock. What they believe is normal and natural guides their breeding selection and therefore which behavioral traits are bred on and intensified.
Your breeding program, guided by your ideal of 'normal' or acceptable behavior, will eventually result in birds that suit that philosophy. I believe it's 'normal' and natural for male animals to be very careful and gentle with females, so mine are, even when the boys are going through the usually terrible teens stages. It took me some generations to get there but the results are worth it. I don't believe it's natural for a male to harm a female, so I don't breed males that do. Such behavior is highly heritable. But kind behavior is also highly heritable. It's really a matter of what you're willing to tolerate in your animals. In the wild, a male who harms females fails to pass on his genes, and the trait dies out with him. In domesticity, he'll be bred if people liked his color or type enough, often with no regard to his temperament.
Personally, I believe it's necessary for a male to leave a female alone if he tries to mate and she rejects him; this prevents her being harmed if for any reason she is not in a good state to mate --- whether she's sitting on eggs or snuggling chicks or ill or injured or whatever. She knows when she's ready, and if he's a good mate she will almost always be willing. Nasty roosters tend to be met with the disinterested attitude of hens, but they force the issue anyway.
Your boys may well grow out of it, the only way to find out is to wait and see, though if they're nasty about it I'd cull. Clumsy and callous or downright nasty are all different things, and only one of them improves. In the longer term, though, you can breed very peaceful poultry if you take a hard stance against bullies. 'Normal' is what you allow it to be. Best wishes.
