There's a decent chance that this year's offense will surpass those 2 years after it plays the weak part of the schedule and Ty makes adjustments.
Mangum has played in what 2 games while healthy? When a true freshman jumps to the top of the depth chart at 2 different positions, that's a pretty indicator that there wasn't much in the cupboard.
Athleticism has very little correlation with being a good receiver. None of them look like they want the ball