Their skin looks pretty good considering they have no feathers, but they seem to be regrowing. My hen had a similar gaping hole in her thigh after a dog attack, we got an antibiotic flush to clean it and prevent infection (we bathed the wound in it once a day until it scabbed over enough to protect from germs). We also kept her separated with a heat lamp (it was late fall) until we were sure the other hens would have no reason to peck it. We got blukote but didn't end up using it, the scab and other feathers camoflauged the wound fine. Since yours doesn't have the feather camo, I would get blukote for sure. Good news is, they can grow back the patch of skin okay, and feathers will grow back there as well.