Males have Favorite females and They are the ones that get torn up the most.A good saddle on each of the hens helps too, but what Walt said is definitely something to keep an eye on. I am not crazy about dressing hens in anything, but the saddles do help keep the skin covered from the sun too.
This is normal though, and some hens will get it worse than others. When they molt they will have all new and pretty feathers again, but they will be bare backed until then.
Walt