re: Why is Archie Manning going down as a great quarterback?

If you don't understand why Archie is celebrated at Ole Miss, it's because you've never actually watched footage from his games. He won some big games and was an innovator at the QB position. He firmly resides in SEC folklore as an icon of his era. Watch the Book of Manning, the ESPN 30 for 30 film, and it will give you a flavor for how good Archie was and why he is still so well-loved.