[Kromm]

Originally Posted by Stupid Jedi

Thanks Kromm, that is helpful to know. But, aren't the vitals just as well protected (or more) in most fighting stances?

Sure, but the vitals are far larger than the head, and also not very mobile. Consider: the heart, lungs, liver, pancreas, kidneys, etc., make up most of the torso, and are spread over 2' across (SM -2). Given that not just any blow to the torso hits them, I won't assume any adjustment for elongated boxes or spheres. They are neutrally mobile (0); they are right at the center of mass, but the torso does twist some, so they aren't rooted in place for +1. They are highly denied (-1), being inside another body part, behind ribs, and one of the areas most protected by most fighting stances. That's -3.

Compare the torso, which is basically the same size or a little larger (but still SM -2), but which gets the +1 for being an elongated box for sure, since any hit there does count. The torso is still neutrally mobile (0); as I said, it can twist, although not very far. It is, however, highly presented (+1), being the root of all the other body parts and the trained default target for virtually all basic attacks. That's 0.

Originally Posted by Stupid Jedi

And, even if the hands are out in front, why would that affect hit location from ranged attacks?

Not "out in front" so much as "presented." A hand that's out fighting, where you can see it, isn't the same as one tucked into a pocket or behind a shield. This is no less true for ranged combat.

Hands are subject to far quicker and more unpredictable movements than the head, yet shooting a hand is easier than shooting the face.

I'd dispute that the hands are more mobile. They might move very quickly, but once committed to a swing, thrust, or parry, they're carried in a very predictable arc until completion. This is assumed to be when the enemy will strike. Low-skill foes haven't a hope in part because they don't know this, which is why somebody with skill 10 hasn't a prayer of hitting the hands (50% -> 9.3%), while somebody with skill 18 won't find it meaningfully more difficult (98.1% -> 90.7%).