Technique counts for more than anything
While I'm sure your facts are correct, I find that technique is the massively overbearing factor. I'm not built for swimming - I'm pretty slim, have really small hands. However, I swim about once a year when I very easily beat 99% of the people in the pool.
I guess from reading this post you might deduce that it's becuase of my massive head, but really it 's thanks to spending seven years doing national level competitive swim training.