Trying to protect things with a shield is exactly what the fighting style is about, weapons not being that different, and I am unsure if I am willing to go to such overlap, however. That's a feature for classes that can take it, and I don't want to undermine viable features by allowing anyone to do that. And besides, often the man with the protector style would much rather have the attack targeted on them, I am quite sure, instead of simply protecting an ally. And if we want the ruling to be consistent, which it has to be if we are allowing the action in this game, I would err towards the side of caution and apply the drawback to every intercepted attack.