Kinetic energy
Just a thought
Concerning kinetic energy, if one wants to compare numbers, simply think that considering the formula means that you get more KE from a light and faster shaft than from a heavy lumbering log.
One has to make the calculation KE = (mass * (speed squared))/2
Anyhow to keep one's feet on earth, take care to measure your actual speed and do the math. Most clubs have a device to measure speed.
There also is the problem of matching the arrow to the bow because some bow-arrow combinations will yield unexpected results due to the acceleration patterns and the timing. Some bows yield more with lighter arrows amd others might do better with heavier ones.
It is better to measure than to estimate.