According to Saints Director of Sports Science, Alvin Kamara's acceleration is....

That's beyond impressive for all three. I would have thought either Olave or Shaheed would have been quicker out of the gate given the size differentials alone.
Well, you just had to bring it up...

https://simplifaster.com/articles/nfl-speed/
(I just skimmed that article and Acceleration as talked about here is measured going from one speed to another. That is, not necessarily from a stop to a certain distance.)