That's fair. Payton has an interesting history with QBs. It's hard to know if he knew Brees would be great or if he just lucked into him. He was apparently right about Mahomes, but he appears to have been wrong about Sean Canfield, Garrette Grayson, Tommy Stevens, and Ian Book. He was also arguably wrong about Taysom Hill to the extent he thought he would be a starting NFL QB.
Sean seems to have a talent for developing QBs Romo, Brees, O'Sullivan, but not so much at picking them out. Although arguably, Winston may not have really gotten better with Payton.