What exactly are you averaging? How can you state he is disputing econ/stats when you don't specify what your ranking is based on? You mention the info includes minicamp and TC reports--what are you averaging there?
What you're actually doing is providing a somewhat subjective evaluation (mainly) based on what you've heard from camps, and (apparently) the number of sacks based on one preseason game, but only half of those on the list have actually played a game. So, yes, he can dispute the stats issue because you don't provide any.