You don't say how old they are. This type of damage is fairly common when they are pullets and cockerels, more than when they are mature hens and roosters. Often the cockerels causing this type of damage don't have much of a spur, so yes, it is the talons. Talons the correct word, by the way. I often incorrectly call them claws. They are sharp dangerous weapons. Once the feathers are removed a sharp spur can cut them, so if they have a spur it can be good to blunt that tip too.
There are different reasons it is usually an immature cockerel problem instead of a mature rooster issue. Often the ladies don't respect an immature cockerel as a suitable father for their children. He's an immature brat, not dependable. So they resist, which can increase the violence of mating. Cockerels often do not have a good mating technique, it's more about force than mutual respect. Their hormones are usually running wild so they don't have great self-control. You said they are amorous. That sounds like a cockerel thing.
They can have what looks like favorites. Sometimes this is the more docile females, they are an easy target. But often it can be the females that most resist them. The mating act is about dominance as well as sex. The one on bottom is accepting the dominance of the one on top, either willingly or by force. Some of the ones they are going after more often and rougher may be ones they are trying to dominate.
Some chickens have brittle feathers. It is sort of based on nutrition and often genetic. Typically it is more about how they digest and process certain nutrients than whether they are eating them, especially if some have the problem and others don't. With 5 of your 10 having the problem I doubt this is your issue. But something that might help "soften" their feathers is to feed them a little BOSS. That's Black Oil Sunflower Seeds. BOSS is fairly high in protein but what I'm after is the oil. It doesn't take much but the oil can help condition their feathers.
You can trim their talons. Like your fingernails or their spurs the talons have a quick. The quick doesn't go all the way to the end but can vary some as to how far it actually goes. If you cut into the quick it will bleed so it can be good idea to have cornstarch or flour handy to toss on to stop the bleeding. On the few occasions I've cut into the quick on spur or talons it hasn't bled much.
I also don't have a video, it takes two hands and I do it by myself. I wrap the bird in a large towel around the wings and lay him down while holding onto the feet, that tends to calm him down. I use a Dremel tool with one of those discs you use to cut metal and clip the point off flat. I don't file or smooth, I figure he will smooth them pretty soon just by walking around. I think the heat generated by that cutting disc cauterizes the wound and helps minimize bleeding. Some people use pet nail clippers, the kind you use on dog claws. At least one lady on here said she used a Dremel tool but used a grinder attachment instead of that cutting disc. Lots of different ways.
Is two too many for ten. There is a myth on this forum that all your problems go away if you have a ratio of 1 to 10. That's based on many hatcheries using a 1 in 10 ratio to assure full fertility in their pen breeding method and really doesn't apply to us. Many of us keep a much smaller ratio and don't have these issues. Others may have one rooster with 20 or more hens and still have these issues. That's even with mature chickens, not pullets and cockerels.
I typically ask what are you goals with those roosters. Why do you want them? The only reason you need even one rooster is for fertile eggs, anything else is personal preference. Personal preference is strong, we all have those, but it is a want, not a need. I suggest people keep as few males as they can and still meet their goals. That's not because you are guaranteed more problems with more males but that problems are more likely. I don't know all your goals, I don't know what the correct answer is for you.
Sometimes when they all mature these types of problems go away. Sometimes they don't. That's why age can be important. Sometimes having more than one male can spur their competition, things might calm down if one goes away. Removing one may go a long way toward solving this issue.
If the entire feather is gone the feather should soon grow back. But if even a bit of the shaft is still there that feather will not be replaced until she molts. With bare skin she may be cut during mating by a talon or a spur. Blunting the sharp tips of the talons and spur will reduce that risk but not necessarily eliminate it. Keep an eye on that and be prepared to separate an injured female because the others might kill her by pecking a raw bleeding wound. If one gets cut I'd be tempted to separate the boys from the girls, at least for a while.
