Well,a heavier arrow will hold it's speed longer than the light arrow.That really isn't what I am talking about but the olympians use recurves at 90 meters.
I had a target bow that was slow by all accounts that I used for 3-d.I shot it at 260 fps,if I were to lighten up my arrow to get 280 fps.On a 40 yard shot,misjudged by 3 yards(37 yards) would impact 1/2" lower with the slow arrow verses the faster arrow.
Probably much closer than you would expect,now,equate that into hunting.Dead deer either way.
It might mean more on the 3-d course BUT,if you are misjudging by 3 yards,you aren't winning anyway.

atleast not in open class.