Basically to cut it short I shoot both trad and compounds. Trad arrow have to be heavier simply because you can damage limbs by shooting too light. Also you don't have the speed that compounds have so you have to make it up by applying more K.E. I don't remember exactly what my compound bow shoots as far as FPS but the K.E. is amazing, somewhere in the 80's. I don't shoot my compounds much anymore, just in extreme hunting conditions, where I have shoot beyond 35 yds.
When the bow is shot all the energy transfers from the string to the arrow, now you have an arrow pushing a broad head. My theory and also those that shoot heavy is because of a high FOC the broad head is now pulling the arrow all the energy has gone to the front. It gives me a better flight and of course more penetration. Yes I'm a lot slower, but also quieter too because of the heavier arrow. I've never failed to have a complete pass through or had bone stop my arrow! I've introduced several that have hunted with me to shooting heavy and they still are. It's no fuss with a compound, all you have to do is adjust your sights, with a trad bow it's not as easy. I won't shoot past 35 with my trad, and shot has to be perfect, losing a lot of energy that far.
Rloving he's on here, makes his own 100gn inserts and shoots a 100 or 125 Muzzy, and I've seen take lots of deer and exotics with his set up.
I'm not saying it's for everyone, a lot of game is taken shooting light. I'm not trying to change anyone, It's just what I do and it works for me, every time!
I know some that shoot as light as they can so they can be faster in case they misjudge distance, to that I say, learn your distance, it's a big part of archery.
I'd rather drop a baseball on my foot than a bowling ball, even if the baseball is traveling faster. I hope this helps, right now I'm not thinking real good, I'm tired I just finished shooting 200 arrows with my trad bow in this heat!