Just about everyone, regardless of equipment choice, has a certain distance where they can hit what they shoot at, every time. What I'd like to see with proficiency tests is allowing the shooter to close the distance to where he knows he can't miss.
Whether or not he has the ethics and discipline to hold himself to that distance when he's hunting is a different matter altogether, and it's something you simply cannot test... But you'd at least force the guy to be honest with himself about his capabilities in order to pass the shooting test.
I see both sides of the coin. There are some scary individuals out there, ignorant about archery to the point of barely knowing which end of the arrow goes where, dumb as a box of rocks and have absolutely no grasp of the concept of ethics. A profiency test would go a long way to weeding out the bozo crowd.
On the other hand, the whole idea worries me. Put some burro-crat (

) in charge of writing the rules for a test and the nitwit could easily come up with a test NOBODY could pass. We're better off without them.