Those numbers mean nothing without context. Roethlisberger played in a team with a great defense his whole career except 2-3 years), and a good running game, he makes the playoffs every year cuz he play in the ****ty AFC, that in his whole career had 3-4 decent teams (Steelers, Colts, Patriots and Ravens).
Eli Manning had one dominant team in 2008, that lost when Burress shot his leg. Bad defenses were the norm, and since 2012 a bad o line. The interceptions are in large part because of Gilbride's system ( Martellus Bennet said so in an interview for Adam and Lefkoe).
Rivers was awful when he had a bad team and good early in his career when he had and underachiever team, he has been good now the Chargers finally are getting better again.
Their career is pretty much equal, good teams = good QB play. And I would rather have Eli and his 2 superbowls mvp than Roethlisberger, who won one of those superbowls despite of his play, and 0 rings Rivers.