Because of the large difference in pass attempts for many QBs, the INT record is a bit misleading (and you can also argue the TD one to a lesser degree). For instance, Blanda now has fewer INTs than Brett, but he threw a pick on 6.9% of his total pass attempts. On the flip side, Brett has thrown one on just every 3.3% of his passes.
So, a better measure is TD vs INT %. I checked the TD and INT % per attempt for some of the best passers of all time (with atleast 8 full seasons as a starter). I ranked them by difference between the two:
Young: 5.5%, 2.6%: +2.9
Manning: 5.6%, 2.8%: +2.8
Montana 5.1%, 2.6%: +2.5
Marino 5.0%, 3.1%: +1.9
Favre 5.0%, 3.3%: +1.7
Dawson 6.3%, 4.9%: +1.4
Jergensen: 5.9%, 4.5%: +1.4
Tarkington 5.3%, 4.1%: +1.2
Kelly 4.9%, 3.7%: +1.2
Elway 4.1%, 3.1%: +1.0
Moon 4.3%, 3.4%: +0.9
Unitas 5.6%, 4.9%: +0.7
Bledsoe 3.7%, 3.1%: +0.6
Aikman 3.5%, 3.0%: +0.5
Fouts: 4.5%, 4.3%: +0.2
Bradshaw 5.4%, 5.4%: 0
So, when it comes to "risk/reward" of some of the top passers of all time, Favre ranks comfortably fifth. For Young, too, you need to understand he had about half the full seasons as a starter that Brett had (and barely made the 8 season cutoff).
So, a better measure is TD vs INT %. I checked the TD and INT % per attempt for some of the best passers of all time (with atleast 8 full seasons as a starter). I ranked them by difference between the two:
Young: 5.5%, 2.6%: +2.9
Manning: 5.6%, 2.8%: +2.8
Montana 5.1%, 2.6%: +2.5
Marino 5.0%, 3.1%: +1.9
Favre 5.0%, 3.3%: +1.7
Dawson 6.3%, 4.9%: +1.4
Jergensen: 5.9%, 4.5%: +1.4
Tarkington 5.3%, 4.1%: +1.2
Kelly 4.9%, 3.7%: +1.2
Elway 4.1%, 3.1%: +1.0
Moon 4.3%, 3.4%: +0.9
Unitas 5.6%, 4.9%: +0.7
Bledsoe 3.7%, 3.1%: +0.6
Aikman 3.5%, 3.0%: +0.5
Fouts: 4.5%, 4.3%: +0.2
Bradshaw 5.4%, 5.4%: 0
So, when it comes to "risk/reward" of some of the top passers of all time, Favre ranks comfortably fifth. For Young, too, you need to understand he had about half the full seasons as a starter that Brett had (and barely made the 8 season cutoff).