Regarding Otto Graham:
It doesn't look as is PFR even tracked all the 4th quarter comebacks or game winning drives until about 1960, which would explain his absence (despite the inclusion of Norm Van Brocklin). Even if those could be found, the season was only 12 games long then and the playoffs consisted of just one game. Without any adjustment for different eras, of course somebody like Matt Stafford or Joe Flacco's raw numbers are going to appear to be better than those of Graham or Johnny Unitas.
Flawed data ... leading to flawed results. Mike Tanier must have just mailed this column in, he's usually more detail oriented than this. Then again this is a column for Bleacher Report rather than Football Outsiders, which may explain a lot.