Darnold, Mahomes (3), Stafford, Manning, Flacco, Eli, Rodgers, and Big Ben were all 1st round QBs some had to get traded to better teams and Brady makes up 7 of the other wins.
So I'm seeing Hurts, Foles, Russ, Brees, and Brad Johnson as the only non-Brady QBs that weren't originally taken in the 1st round. Foles and Johnson were absolutely carried by their loaded teams. So the odds of drafting a Super Bowl winning QB not in the first round are really low and two of the recent 5 not named Brady are QBs you wouldn't want to really build around. Hell Foles is probably available right now.
If you are looking for any sort of odds from this data is might be to sign a former 1st round QB that struggled on a bad team or keep drafting 6th round QBs and hope they magically turn into Brady.... There is also the build and elite defense and plug whoever you want back there with Hurts, Foles, Russ, and possibly Darnold.