So we know BB wants the next QB in place. We all do of course. It looks like he is not looking to trade JAG. However I really question that move (depending on how reasonable the asking price is). This is because with a little research we can see the difference between good and great QB play is huge when it comes to winning.
But lets look at great QBs only at first. Of the 51 super bowls won we have HOF QBs (or borderline ones waiting to get in) winning 40. Brady 5, Peyton 2, Brees 1, Rodgers 1 Ben R. 2 (not in yet but likely will be. I added their wins to the HOF group and got 40 of 51).
Even if you question Namath and a few other HOF QBs (I do as well) it is clear that great QBs (HOF level) hold about 75% of the super bowl wins vs the rest of the NFL.
To look at this another way that means QBs that are just very good but not HOF don't tend to win regularly. Looking at good but not great QBs you might have a Russel Wilson or Eli Manning who may win if they got hot and the stars align but history is litered with very good QBs who never won.
Just guys who were active in the past 15 years. McNabb, McNair, Ryan, Rivers, Cousins, Stafford, Romo, Luck, Pennington, Bledsoe, Garcia, Hasselback, Newton, Palmer, Green, Gannon. They never won anything but are QBs your team in general would be happy to have. Considered on the top 10 most years. I am sure I am forgetting a few very good ones just in that time frame.
The point is even if JAG turns out to be a legit Good QBs the odds of a "good" QB never winning is more likely than winning by a large margin. You need to be great to give your team a high likelihood of winning a championship at some point.
However the odds JAG will be that is pretty low not cause of him but just cause it is hard to find HOF QBs. What is comes down to is your odds are much better with a few years of elite play compared to 10-15 years of good play and it is not even close. Maximizing Brady is clearly the answer if you are looking to win the most super bowls you possibly can. Even if Brady only plays 2-3 more years it is still the better option statistically.