Could they see each other before they were together in same cage? Sometimes that can help, a little like the play pen method for integrating chickens. So the girls have some time to get used to him before they can touch each other.And the little jerk is covered in her blood!Bad avatar! He got split out for the moment too.
I'm kind of on the fence about this guy because I do select for aggressive fertility and part of that is aggressive mating tendencies. My birds are kept in really unnatural pens compared to some people's and I kind of have to just expect a certain amount of unnatural behavior there too. I'm tempted to try and rig up an area 2-3x the size of their current space just for this breeding group and see if that mellows them out.
He also was without ladies for a while because of the bumblefoot way back when (happy to report 100% healed and eliminated for a while now), so he's been pent up.
On the other hand, doing well in that confined space is also something I'm trying to select for, and I gave the little butt three hens at once to try and mitigate that and he still tore one up.