The article is in the context of terminal ballistics on people, focuses on handgun calibers, and explicitly states velocity is not the key (numerous times)....and yet here we are throwing out velocity thresholds.
The bullet geometry, material properties (i.e. young’s modulus, moment of inertia, cross-sectional area, etc.) and the forces imposed (found from the work-energy relationship) will dictate material strain. Speaking only in terms of generic velocity really oversimplifies what’s going on and doesn’t take a look at the whole picture. Velocity in-and-of itself does not cause material strain.