Most important, what would the bottom-line championship count be? Would Manning have locked down those three Super Bowls for New England? Would he have achieved a different result against younger brother Eli in Super Bowls XLII and XLVI? Would Brady's tenure in Indianapolis have produced more than one title? There is a sharp division in this category.
NFL Network analyst Charley Casserly, who has three Super Bowl rings from his 23 years working in Washington's front office, thinks that Manning -- who has a famously spotty 10-11 playoff record -- has sometimes been a victim of his own spectacular ability.
"Peyton's unique," Casserly said. "He's usually flawless at executing, OK? But the Achilles' heel he faces comes in playoffs. My feeling is that too many times it comes down to Peyton to make the right read and the receiver to make the right cut. It's tough when you're in the playoffs and you are slicing it that fine.
"There's been too much on Peyton's plate, too much responsibility. Brady never had that kind of pressure in New England. He always had a defense and a running game to support him."
In other words, Manning would have done just fine in New England.
Polian, who ran the Colts from 1997-2011 and is now an ESPN analyst, made the ultimate decision to draft Manning.
"Teams win football games, not individuals," Polian said. "The Brady teams that won the Super Bowl were the preeminent teams of the era. Hard as it is for me to admit it, they were just better than we were.
"The Patriots are decimated on defense, but week in and week out they have the best game-specific plan of attack. Under Belichick, they are the best-prepared team in the league. That might have more to do with the final outcome than who the quarterbacks are."
What if it had been Tom roughhousing with his brothers, Cooper and Eli, in the front yard of the Manning's grand, yellow house in the Garden District on New Orleans? What if Tom had received the DNA of a gifted NFL quarterback and gone to Tennessee instead of Michigan? Would he have developed into the No. 1 overall pick?
How would it have gone if Peyton was a Bay Area kid, weaned on Joe Montana and the San Francisco 49ers? If he'd scuffled and strained at every level to develop a football IQ? Been drafted after such legendary players as Hofstra's Giovanni Carmazzi and Southwest Texas State's Spergon Wynn? Would he have developed the fierce fury to prove everyone in the NFL wrong?
Cornerback Ty Law was a Brady teammate for five years and finished his career with nine interceptions of Manning, the most by any player.
"In the beginning, we weren't expecting Tom to play well," Law explained. "The defense just told him, 'We got this. Just don't turn the damn ball over.' I think if Tom's on the other side, we would have shown him what defense was.
"Peyton would have more support on our team, and that would have leveled the playing field. We had so many leaders, particularly on defense. Tom didn't have that pressure to lead. On our team, Peyton would have relaxed a little bit more.
"What drove Tom was being the forgotten guy, and that's why he approaches the game the way he does. When we need one play and you ask me, 'Who do you want to have the ball?' for me, Tom has the edge."
Through the miracle of cinematic license, imagine that the Patriots hooked up with Manning in 1998 and the Colts took Brady two years later.