Hitting Targets of Opportunity in Combat

[VariousRen]

In combat attacking the torso is a -0 hit location, and attacking at a randomly determined hit location is made at no modifier as well. Watching some HEMA duels and reading reports of shootouts has pointed to a lot more attacks landing outside of the torso. This is especially apparent when opponents are just trying to score a touch, not an actual blow.

To nudge combat to be a little more in line with what I've observed, I'm considered giving a +1 bonus when taking a random hit location. My reasoning is that the whole human body is larger than just the torso. Additionally there are situations and movements that aren't simulated by GURPS that might present one hit location more than another, and a blanket +1 would represent a character taking advantage of them to land a hit, instead of aiming for a hit location like the torso where a hit is guaranteed to do good damage.

Is the general +1 for a human bodies size reasonable, or is there a good reason that both torso and random hit location are -0 hit locations? Has anyone tried something like this in their own game, or have advice that they think would be useful?