There must be different gearing options for the different areas of the nation. Obviously someone with a flat landscape would benefit from a set of high gears (Numerically low) while the mountain dwellers would benefit from a lower gear (numerically higher)
My two YJ's were completly identical, same years, same everything except for two options. The color, and the gear. My first YJ was from NH which is very mountainous, it had 3.55:1 (or 3.54:1 whatever) my current YJ was a southern vehicle and has 3.07:1.
This is a theory though, I have no proof that Jeep does this, But I know for a fact that chevrolet does with the 1 ton's