You think?????
The startup of racing with Brushless had the ESC of the month, continious new ESC's performing better, it took a while that the hardware stayed the same and firmware updates become possible.
Even in stockracing with all the same motor and a blinky ESC there are a lot of perfomance differences on the track, for sure if you use a box stock motor it will have the worst performance.
Again, shimming is most important. Using a motor analizer to read the sensor positions and with the solder iron to outline sensors to be equal and even with morte timing is also done to gain more performance. Rewinding stators to get a shorter wire is still possible on races where the resistance limit is not meassured. The new trend is to replace the 3 scres of the housing for titanium or another non magnetic material.
Not to mention cheating tricks like mounting a blinking LED in the ESC that it stays blinking no matter what program is used.

And the list goes on......

Most of the tricks are based to gain extra sensor timing so get rid of the sensor timing and stockracing will become even more simple and more equal.