The golf ball delivers much much greater energy to the guy's head.
Energy delivered to the target matters.
If you don't believe me, you provide the test head and I'll provide the ping pong ball and the golf ball.
I'll step up and take you up on that offer!
Provided one teeny tiny litte detail....
I get to call the range...say,,200 yards?
It's all relative & it's all the different pieces of the ballistic puzzle.
Depsite having a lot of "muzzle energy" a foot or two away from the T.
Downrange, that golf ball hasn't got enough left to resist being thrown off course by a blade of grass.
OTOH - no way no how would I stand in front of a ping pong ball launched from some device that could toss it 6 or 7 thousand fps.
Again - I keep going back to what I concluded...
Velocity is the more critical figure I'd want to know. The energy will either be there or it won't.
Velocity is also a much better indicator of how far downrange I can go & how flat the round will shoot.
Energy figures don't really tell me that.