There are a lot of things that happen when a rooster mates a hen. When the hen squats, she is spreading out his weight. If she tried to stand up during mating, she would probably hurt her legs with all that weight, but if she squats, that weight is not as bad as it seems. It's kind of like if you take a needle and push the sharp point into your skin, you can hurt yourself, but if you turn the needle sideways and apply the same force, it won't hurt you at all. Most roosters are a few pounds heavier than the hens of the same breed. There is always a chance that the rooster can hurt a hen, especially if there is a great deal of difference in their weight, but if she squats, it is usually not that big a deal.
When a rooster grabs the back of a hen's head, it is not just to hold on. That is her signal to raise her tail up out of the way so he has a good target. But a rooster also uses that grip to help him force a hen that does not willingly submit. Sometimes those feathers coming out are due to the rooster's technique. Sometimes it its more due to the hen not doing her part and willingly submitting. I don't know of any saddles that address the back of the head.
I find that the hen to rooster ratio has little to do with barebacked hens. It can be a factor, but with my flock it is usually a pretty small factor. That 10 to 1 ratio you keep hearing about is more about fertility than bare backed hens or roosters fighting. There are posts on here of people that have one rooster with over 20 hens and still have a lot of barebacked hens. Sometimes, that may be because it is an oversexed adolescent rooster that the hens do not willingly accept. That situation may improve as he matures. But with that many hens, he is more likely a brute that needs to be replaced. Or he is such a wimp that the hens will never willingly submit to him, so they always resist. He still needs to be replaced.
I've seen posts on here of flocks that had more roosters than hens and yet did not have any barebacked hens. Many breeders keep one rooster in a pen with one or two hens and do not have a problem with barebacked hens, especially if that rooster is mature. I've had more problems with barebacked hens with what should have been better ratios. There are a lot of factors that go into a hen being barebacked, some due to the rooster and some due to the hen. Sometimes adding a few hens can help the situation, so ratio can be a factor. But I find that other things usually outweigh the ratio, expecially the rooster's maturity.
I've had a situation where more than half my flock of 10 hens was barebacked. The rooster should have been mature enough that his maturity was not a problem. I replaced him. I have had the situation where one or two of the hens were barebacked and the rest were fine. Those hens did not make my breeding flock. If it is only one or two hens with that problem, I figure it is more the individual hen's fault than the rooster.
