See my point? Theoretically, sure, you're probably right. In a combat simulation, it probably works the way you say.
I hate to break this to you, but we are talking about a combat simulation. What do you think the combat chapter of any RPG is?

My point is that the raw mechanics of a game system should not favor one thing over another simply due to an artificial assignment (like hit locations). Perhaps the designers intended that if you take two identical amorphous blobs and divide one into 5 hit locations and the other into 7, the one with seven is going to be a little more likely to survive, but I kind of doubt it.
Yes, you are absolutely correct; this may be irrelevant at most tables. But just because something doesn't have an impact on most tables doesn't mean it can't still be flawed.
Who, in their right mind, in a system as potentially deadly as RuneQuest (because *EVERY* version of RQ is far more deadly than *ANY* version of D&D and most other games), is going to send their character up against something like a scorpionman or chaos centipede and only try and chop off it's legs?
Of course no one will intentionally strike at it's legs. But with something with a lot of legs, statistically, that means your're going to roll legs more often on the random hit location check.
Precise shots are fine, but if I'm sitting at 60% attack, and the BBEG I'm fighting is at the same or higher, reducing my chance to hit to a mere 20% while he retains his full chance to parry is hardly what I would call the best call. While you may make that hit count more, I'm as yet unconvinced that it's worth taking three times longer to do so.