a simple yes or no answer would suffice.
the way you ran at recess in 1st grade was your bodies resultant solution to the being chased by the other kids, or to get from first base to second base.
i would guess Boston Billy didn't run the same for the marathon as an adult as he did as a child playing a tag football game.(although salazar might have) he evolved into that for endurance running. Solinsky probably looked different running his 2 lap warmup for pee wee football than the style he has evolved into now. (but you are right i have no first hand knowledge of either)
when you watch children move, you see who has the nervous systems and proprioceptive awarness to solve movement challenges.
why do some strike on heels, some on toes, but most flat? why not an equal random distribution if it truly didn't matter?
if it didn't matter, why wouldn't one run like a gymnast or even a ballerina?
my point is it matters. and there are better and worse ways. for people like you who say you don't choose how to run then some people just happen upon or evolve into an efficient way. some don't evolve into an efficient way and stay with an inferior technique that limits the result towards their maximal potential. or for those that believe in coaching (or change through observation of others) you can choose to run a more efficient way by emulating others, or by understanding the biomechanics.
so again i ask, if 2 people are equal in all other physical aspects, would the techniqe used in their running have any outcome on the result?
do you choose your handwriting style? can it be improved through proper coaching and training?
and proper information and coaching during the formative years can make a large amount of difference.
So 1 more time. All else being equal, technique will make a difference in the outcome of not?