total yards is not a terribly telling statistics. even then, montana had 2 seasons close to 4000 yards
look at yard per pass attempt. montana=7.5 for career, which still stands pretty well among QBs today
or tds/int ratio, which still stands VERY well. or playoff performance.
total yards passing is almost the most useless stats for evaluating a QBs performance
obviously the game has changed but then you cant compare them at all, because there is no way to compare them in vacuum.
either way, rodgers is easily the better decision-maker, which is the #1 responsibility of the QB. he is also far less dependent on his oline as he is amazing outside of pocket (has better qb rating outside of pocket). I dont really see many arguments for favre besides the fact that he played in a tougher era. arod can make every throw favre can make, and do it more accurately while spreading the ball around, and if anything you have to worry about his mobility.