If I follow your analogy, you are saying that you will take the average girl (Trent Dilfer) over the hot cheating wife (Dan Marino) because the average girl will come through for you day in and day out.
That analogy is all wrong. Trent Dilfer (the average girl) did not come through day in and day out, he was a JAG at QB and that is why the year after the Ravens won the SB with him he was kicked to the curb.
If the average QB comes through day in and day out, guess what Judas...............he becomes the hot girl!!! He starts going to probowls and he is then thought of as a great QB.
Dilfer never did this, he was a JAG and only won the SB because the Ravens had one of the best defenses in the history on the league that year. It literally didnt matter who the QB was.
So does that mean that you keep the average QB that leads you to a SB ring or do you try to upgrade to a better QB regardless???............The Ravens apparently figured they could do better because after that SB win, Dilfer never played another down for the franchise.
So your analogy is totally whack, just because a team wins DESPITE THE QB, doesnt mean you choose to go with a lesser QB. Any GM that hasnt had a lobatomy would upgrade to Dan Mariono over Trent Dilfer regardless of if the team won the SB or not with Dilfer.