I think McNabb is the perfect example of when they talk about the Hall of Very Good. If he made the Hall of Fame, eh, cool, he had a memorable career. If he never does, I don't think by any means that it would be a travesty. He's kinda like the grey line in between.
But yeah, comparing McNabb's career to Troy's is a joke. Aikman gave up a lot of stats for the game plan, a game plan that won Dallas 3 Super Bowls. When they needed Aikman to save the offense, he aired it out and punished defenses. It just turned out that more often than not the defense had no answer for Emmitt.