That was literally my idea–put the Academy head on every other skin :^)
Flat crit reduction is a neat idea, but I do think it needs to be significantly smaller. If you miss D.Va’s head–however unlikely it is–you still get a bodyshot. You’re still rewarded. If you miss a headshot on pretty much every other hero, you’re at about a 50%+ chance to hit thin air. It’s not really fair.