This guy did the same thing I did a few years ago (though for all positions). Easier than trying to find that one, so here ya go:
https://www.milehighreport.com/2017/6/28/15880748/success-rates-of-drafted-quarterbacks
Hall of Famers:
13 drafted in the 1st round vs 14 drafted in ALL other rounds and free agency. Only 2 of the latter were drafted after 1980 (vs 5 in the 1st round), eventually 4 with Tom Brady and Drew Brees, but that will be countered by Manning, Rodgers, etc. That gap is only going to grow as scouting continues to improve.
So, as far as your "guarantee," nothing is ever guaranteed. It's sad that that needs to be said. If I offered you two procedures, one with 81% survival rate and one with 48% survival rate, but cheaper (and not that much cheaper as you're still most likely missing the playoffs), you would choose the Favre 48% route? Or would you hold out for the mystical one with a guaranteed success?