I’m sorry, there is literally no way that Elway or Brees can be considered greater than Brady. Manning is also out, but at least it is a somewhat close call. Most people would probably be 50/50 on Brady vs. Montana. Brady has become even better at this late stage in his career, with a revolving offensive line, inconsistent run game, and no deep threat whatsoever. Every quarterback you mentioned played significant parts of their career with HOF-level talent at RB or WR or both.