Many many ppl cannot run NATURALLY correctly, thats a horse crock. I see ppl over and over again who cant run period. Typically i see those that are more NATURALLY fast than others, is because they CAN run correctly without thinking or training. You know the guy, the guys who runs 11.1 in grade 11 and doesn’t train ever. Technique they just KNOW what to do. The rest of them, like 99% of the population, run like chumps.
The styles i see everyday from ppl doing an attempt at “running” is crazy. Even JOGGING people get wrong.
You wont learn to run fast correctly until you learn to run slow correctly, and do drills correctly.
Just getting your technique down, could involve any or all of the following
1 - knowing what to do
2 - doing that in the right order
3 - being tight in certain muscles
4 - being weak in certain muscles
5 - being too strong in certain muscles compared to other muscles
and the list could go on.
Sorry for the rant 