The first "Top 1" QB pick that comes to mind is Alex Smith. Undoubtedly there have been others. Which do you have in mind as "Brady/Rodgers/Mahomes level"?
Yeah, if a person could see the future, he'd draft Peyton Manning. Luck definitely not. Even in that weird circumstance, slam dunk sure to get the next Peyton Manning, I'd say hell no to tanking, and I'm pretty sure the Packer organization would to.