There’s the key. Your body will find its most efficient form according to its current fitness level and strengths/weaknesses. If you want to increase your stride rate, you should probably be doing what some people call “fast foot drills”.
I don’t know why. There is reason to believe that shorter runners hold an advantage over taller runners in long distance events. Just take a look at some of the elites and you might realize there is likely some truth to this, as most are much shorter than most people who only see them on TV and in pictures think.