10 would be Russell, but what would be 1? I'll make it that 3 is the least competent to play in the NFL, like a Pennington. 7 would be the "average elite QB".
Troy Aikman - 7 (arm overrated, threw a lot of jump balls)
Terry Bradshaw - 9
John Elway - 8 (only watched him late in his career)
Jim Kelly - 7 (played in the cold, so that could affect it)
Dan Marino - 9
Joe Montana - 6 (people say that Montana had a really weak arm, but that's not true. You know that throw he made to Clark against Dallas, not the one in the last seconds, but that where Montana was being held in the legs and Clark came passung through the middle? That took a lot of arm strenght)
Moon - 9
Young - 7
Favre - 10 (might be bias in here, but I've seen Favre make impossible throws
Manning - 8
Brady - 7
How would you have it?
Aikman - 7
Bradshaw - 8 (but I havent seen a ton of games of his to be honest)
Elway - 9
Kelly - 8
Marino -9
Montana - 6
Moon - 9
Young -7
Favre - 10
Manning -8
Brady -7
so pretty much an agreement. Now if you take all the guys with the big arms you get 3 SBs. Favre's 1 and Elway's 2. You could argue that Elways arm wasnt what it was when he won those.
While arm strength might get you into the NFL, it doesnt mean much as far as winning titles.