What you say about KE vs. Momentum is true. But, how much MOM do you need to get thru a whitetail? At some point, you start sacrificing drop due to reduced speed. Too much drop and you need more pins and accurate range estimates to make ethical shots.
I have my ancient old compound shooting 220 fps. I use 2 pins to 30 yards. Shoot Muzzy 110 gr heads with really not so sharp points. And have never had an arrow NOT go thru a deer or hog and stick in the ground on the other side when shot out to 30 yards.
You need enough MOM to get the job done. After that you're just sticking deeper into the ground on the other side. It's a balance.
