I can't believe your roo survived those injuries! YOu are a wonderful chicken mama, I would have put him down, thinking there was no way he would recover!
I do second other people's comments about predators. Are you sure something wasn't reaching a paw through fencing or anything, and those boys were fighting to protect their hens? I have rooster and turkey toms fight all the time and rarely do they hurt each other. Certainly hard to believe they could break beaks and rip up combs.
We used to raise our meat birds in moveable crates. They wre so heavy, nothing could lift them up to get under. But on a warm night, the birds would pile up against the fenced in side (there was a side that was solid to protect from wind, rain and sun) and we often found ones with scratches and gouges and even bites missing from them, but no critter had gotten in, they were reaching through the wire. They did some decent damage that way. These were meat birds, and were pertty young. If it had been hens, and adult roos, I bet those roos would have tried to fight back. I've lost a few roos that way.
We haven't had rats (I hope we never do) but I've heard that the damage they can do is astounding, and you;d think it was a much bigger predator. We'd be in big trouble if there were rats in our area. We have penty of mice, attracted by the chicken feeders, and they can get into anything, but they don't attack the birds. I can't imagine if rats were following suit...