A lot of rifle hunters are pro shoulder shots through the shoulder blade itself. While most shots do go through into the lungs, but what about bad angle that can and have deflected a bullet?
Then we add this scenario in to archery hunting. I have personally never tried to shoot forward onto the shoulder always behind it. But then again I have seen quite a few people stick a arrow into an elk shoulder and it just flat stops right there on the bone. Not a good thing. Of course whitetail deer have less bone density but it could still turn a arrow on a bad angle. No I'll not take that shot. But accidents happen and when they do I'll take a fixed broadhead to weigh the scales and hope it got in there deep enough.