I mentioned in a comment that I posted a poll on RPGnet asking opinions on whether a person's strength, mass, or both could/should affect how far they can throw a weapon. There actually wasn't that much activity, although what little there was came down strongly on the side of Strength influencing throwing distance. I'd call the results inconclusive, though, since the poll numbers are so small and there was no discussion.
However, in the only reply to that post, IvanMike pointed me towards a website about the physics of throwing knives. It doesn't deal directly with the question at hand, but it does state directly that the speed of a thrown knife depends on the power of the thrower and the way the knive is thrown. Greater speed means more distance, as long as the knife thrower remembers to aim a little higher for targets at a greater distance.
Not that actual physics makes much difference. Although I like my rules to make some kind of sense, my primary concern is balancing the need to keep Liber Zero flexible and true to the original rules against the need to make something distinctive that isn't as prone to accusations of infringement. For this reason, I think I'm going with the alternative rule of setting short missile ranges to 1" and adding the length of any "launcher", such as a bow, excluding mechanical launchers like crossbows, which are fixed. Or perhaps I'll consider tying ranges for mechanical launchers to the time and manpower needed to crank or prep it, which Roger suggested.