The point is, Elway only once led the NFL in anything and that was passing yards. His MVP season of 1987 he didn't even finish in the top 10 of some categories. He's in because he played in 5 Super Bowls.
Because Stafford basically missed his first two seasons in the NFL. Stafford was at least at one point the all time leader in yards per game. Matt Ryan has played over 40 more game than Stafford and averages fewer yards per game than Stafford.