Other than Ty Detmer, he is probably the most decorated LDS college football player. He pretty much got every award he could other than the Heisman.
Its definitely arguable that the awards were heavily influenced by Notre Dame's undefeated season combined with the media's latching onto the "feel good/feel sad" story about the death of his grandma and "girlfriend".
But neither Star or Ngata received anywhere near the level of praise that Manti got at the college level. So that's why I had him number 1.