That was nice of Peyton. But that was 20 years ago and Manning was already a league leading passer and a 2 time Pro Bowler averaging over 4100 yards and 28 TD a season before Caldwell showed up. Plus, the 2 are light years apart in where they were as QB's coming into the NFL.
Plus, Manning was an immobile pocket QB smarter than most QBs and Fields, a modern dual threat QB, is like no QB Caldwell has ever coached.