Thats a refreshing idea, Impact.
Instead of worrying abour how many yards the target is, you have your own kind of built in system. I bet your mind can determine paces-away easier than yards-away.
BTW, I WOULD let an arrow fly at the buck in the picture. But I practice at 40yds even more than 20yds.
I bet you don't get too many bow shots on elk less than 30. One day I will find out first hand.