What's wrong with this idea? It's in NLHETP. I'm sure Sklansky would believe one or two of the six is holding an ace or king. The fact that they're weak, live players only increases the odds of holding an ace. They always limp with Ax. Sure, they can limp with most anything, but aces and kings are good possibilities.
Stop discussing "luck" and discuss this!

Can one assign a % to the chance that someone folded one or more of our cards?

At any rate, this % is probably negated by the % that he has a worse A himself or some random junk hand.