I assume you are asking me. I dont know unless you have a video of them.
AAgain, just watch the feet and they will tell you.
As far as the gal in the video, contributing to ball speed, her legs are adding next to nothing in that category. As I said, hers may be the shortest, weakest and slowest stride I have ever seen, outside of very young beginners.
Rogers? Rogers drive is close to 7 feet and she cruises in the mid 60's.