Barnwells write up was on point. Mannings season was really good. Petersons was a statistical outlier, a historical season, a season that has a lot of astounding mitigating events, such as being on a team with a terrible passing offense and the severity of his injury. Manning didn't play in 2011, Peterson did, and was hurt in December, and returned in September.
Theres a lot of things we can consider, but for Mannings season to be as good as Petersons he would have to have been 30% better than the typical league leader in production at his position, meaning for a 21st century QB, about 5500 yards passing.
If Peterson doesn't get it, expect me to troll about his lack of heart. That said, he earned it.