If he's a pet, not dinner, then he would benefit from having a hen. So would the other.
As to whether or not he will be nice to her, that depends on him, his parents, and the instincts he inherited. He may have inherited instincts from a male who lived a fairly natural family life, roaming with his mate and other poultry, or he may have inherited instincts from a male who spent his life cooped up away from hens until it was time to mate, probably spending his every day displaying and gobbling at other males in the same 'battery-stud' situation, becoming almost psychotically frustrated in a mental loop that never reached a natural conclusion.
I've had toms from fathers from both circumstances, and the more natural the life, the more natural the behavior, but the more restrained ones tended to eventually take out their frustration on the hens, never being able to access other males but seeing them 95% of the time compared to almost never seeing and interacting with hens.
Yours are only young, I'm guessing. Living a natural or close to natural life will always benefit them, so if you can give them a more natural life, go for it.
Time will tell. Best wishes with them.