All the comments about how velocity is important but energy isn’t make no sense. The two are so closely related you can’t change one without changing the other. For a given projectile if you alter velocity you also alter its energy and vice versa.
As far as saying a projectile requires a certain velocity to expand/upset/fragment, you could just as accurately say it requires a certain amount of energy to expand/upset/fragment. A required amount of energy would possibly even be a more accurate statement as it’s the energy resultant from the mass and velocity of the projectile that’s actually doing the work of expanding the projectile.