“The NFL ranked Favre” is funny enough on its own.
If Brady wins his third this decade, you could make a strong argument that Tom Brady 2000-09 and Tom Brady 2010-19 are both separately deserving of a top 10 all-time ranking.
2010 Favre would've been wrapping up his HOF career, sitting on a bunch of stats and records at 40 years old. Brady would've just gotten through the so-so 2009 season with a wild-card round loss in 2010.
It's also a difference of 50+ pounds on the OL. A lot of players from back in the day simply couldn't translate to today, while some of the lesser players might actually be better with a different training regimen.
And the same would be true if you went in the other direction, from today to yesterday.