When reading about foot pounds of energy – some tables provide nice big integers to toss about.
Energy is scalar, strictly a measure of magnitude without vector or description.
1,000 ft/lbs means the object contains enough kinetic energy to move 1,000lbs- 1 foot vertically or horizontally, or 500 lbs – 2 feet vertically or horizontally and so on. Now take your 9 MM with a 124gr projectile at say 1,300 fps at the muzzle. That’s roughly 465 ft/lbs of energy. Lay that muzzle against the side of a 230 lb object and you should move it roughly 2 feet. Ever seen that happen?
Energy is completely specious until you can describe precisely the work being done with the vector or so I've been told.
That Hornady ad is a tad deceptive, as it talks about kinetic energy and the tearing of tissue - the bullet's diameter is responsible for mashing and tearing the tissue.
A larger wound creates a higher probability of hemorrhagic shock, the precursor to primary shock. Larger wounds bleed more, larger wounds destroy and/or macerate more tissue, and larger wounds have a higher probability of disrupting nerve plexuses. These are the mechanisms of incapacitation and the larger diameter bullet creates a larger wound, all else being equal.