At the elite level, even at the national level maybe, you have to think of it as complex, because a mere .01 can be the difference between 1st and 2nd place, going to the Games or not going, or qualifying for nationals or not, or medaling, or not.
Think about it: .01 "Running naturally" is over-rated...every sprinter in the modern era who has ever been great has been highly trained, and has had a good coach around who tweaked parts of their race.
Running fast isn't complicated, if you're a fast runner--however, running to your full potential, and increasing your performance envelope, are complicated, when the race is as quick and energy-intensive as a 100 or 200.
Especially the 100. I have always said that with the exception of Ben Johnson and his first 10m, an athlete cannot "win" a 100m race, but that the 100m race can only be lost.
The 200m is a bit different--an athlete can definitely work to win that race, as Blake did in last year's final in Daegu, when he switched gears as he was about to get passed by Dix. The fact that he had another gear to switch into tells you that the 200 is a much more tactical race than is the 100--or at least that the tactics can be implemented through will.
In the 100 they must be implemented through training, and training must be very specific. Look at a guy like Jimmy Vicaut--he has fantastic native speed. If he had any coaching worth talking about, he would be running low-9.90 already...or, if he is impossible to coach, then he should switch to the 200 immediately.
Whether you like the USA or not, it is undeniable that we have some excellent sprint coaches here--which is why internationals come here to train. It's not for the weather or the food or the pharmacy, it's for the coaching.
And those coaching methodologies, and the types of races they produce, have been exported to different countries around the world. Why? Because they work. And they are anal.
It takes a whole life's endeavor to produce a 100m champion--and I'm talking about the coach's life, not just the athlete's. Except for one in a million, a good athlete will never be great without a great coach.
There are some, I will grant you that--Bob Hayes and Usain Bolt come to mind...guys who would win a 100m race if no athlete ever received any coaching, and they took us naked out of the jungle, put us on a track and said "run from here to there when you hear the gun".
But if totally uncoached, even they would lose against a well-coached Tyson Gay.
Well, except maybe for Hayes, who was the best 100m guy ever.
Anyway, yes, it is that complicated at the highest levels.
A race can always be over-thought, however, and then you end up with a racer like Lemaitre. He needs better coaching and training, so that he doesn't have to think as hard.