Great response! Just to add a bit, start with the game you are hunting. For whitetail deer with a modern bow and a well placed shot and sharp broadhead, kinetic energy is not a factor. If you are taking long distance shots and spraying arrows and are concerned about hitting a shoulder bone, again, kinetic energy is a non-factor. You can't get enough to penetrate a shoulder and get a good low exit wound with a blood trail that gives you a high probability of recovery.
Reduce shot distance (I restrict myself to about 20 yards) and take only good shot angles. That will get you 90% there.
The second biggest factor is poor distance estimation. Some folks try to shoot a very fast bow to overcome this. As you stated in your response, shooting a quiet bow is more important. Distance estimation error can be compensated for in other ways. An average modern compound will shoot pretty flat out to 20 yards. If you limit your range to that, you remove pin selection mistake as a factor. By using a laser range finder to range trees when you first enter your stand and memorizing the distance you can all be eliminate ranging error at ranges under 25 yards. If you are over a field, a safety flag at 20 yard and possibly 30 yards accomplishes the same thing.
So, back to kinetic energy. Your math is right . Folks should understand that velocity is more important than mass because it is squared in the equation when it comes it kinetic energy when the arrow leaves the bow. However, what you are concerned with is the retained kinetic energy down range when the arrow impacts the deer. Mass in the arrow helps retain the energy down range, but more importantly is the tuning. Having the correct spine given your setup and a well tuned bow reduces the volatility of the arrow faster when it leave the bow. The means less energy is lost to drag in addition to a more accurate arrow.
Just trying to expand on a good answer for others...
Thanks,
Jack