Crap formula. Velocity always will be the most important factor in this formula. Smaller calibre, lighter bullet but a very high velocity always wins out.

Also at some point better shooting is always so much more important.

If I brain shoot an elephant,buffalo, lion, etc with a .318 WR 250 gr FMJ, is it inferior to a .500 NE chest shot?

But it is easier to shoot.

A good reason to have calibre cartridges in a competition in groups and minimums as well.

Easier to shoot a 7x57 on paper targets than a .450 NE. But the "opposite" on real dangerous game for most people and circumstances.