To play devil's advocate, majority of these guys you just mentioned had really good defenses and rushing attack, the Saints don't have that. Regarding Nick Foles, he came in on the back end of Wentz who was having a good season till he got hurt.
LOL so we build a really good defense and run the ball well. Guess what Mahomes has a really good defense. Jackson has a really good defense Even the elite QBs have good teams around them.