Just on the surface I can say that several things about this means of measuring does not measure true ability nor accurate comparisons.
Lyle Campbell played on one of the most unathletic teams to ever win a six-man football championship. I watched three of his playoff games in person and two regular season games on tape. These five games showed in vivid shocking detail how half his teammates (not Kite or Johnson) dropped almost half the balls thrown to their hands. Literally, versus Panther Creek Campbell had six or seven passes dropped to receivers who were facing the thrower when the ball arrived. Stationary patterns. In 2012 Dakota's receivers dropped about 30% of all passes thrown to them. During the 2005 football season I would estimate that Tyler's targets dropped 25% of passes that hit them in the hands. Not referring to poorly thrown incompletions. Darius Kimberling had dozens of balls dropped in the three films and one live game I watched.
Another inaccuracy I see is the lack of passes attempted. Someone who throws fewer than say 100 passes for a single year will not have enough attempts to warrant comparison to those who throw 150 or 200 passes for three or four seasons. . Throwing less than 30 TDs cannot be compared to someone who consistently puts up numbers in the 40s, 50s and even 60 TDs.
Longevity should be a major element in comparing passers. Guys like Tanner and Dakota Woods, Lyle Campbell, Howard of May and Tyler at RS who played QB for four years, completing hundreds of passes and completing a hundred and two hundred scores is proof of their ability way beyond anyone who manages 50 or 60 completions and 25 TDs in one year of varsity passing. How can you realistically compare someone's throwing ability for one year with so many who threw with the same results for three or four years?
It would be better and more accurate to factor in a survey of the top coaches of the last twenty years to find out their opinions of who the best passers, rushers, receivers and defenders have been over those years. If you interviewed say ten or twenty coaches and eliminated the player or players they coached, that information would be much more accurate than using statistics only as a measuring tool.
Who are some top coaches? That's easy to identify. Here are a few in no particular order:
Vance Jones, Nelson Campbell, Mitch Lee, Dewaine Lee, Jerry Burkhart, Karry Owens, Brett Tyler, Mike Reid, Doyle Clawson, Bobby Avery, Trey Richey, Mike Bigham, Coylin Grimes, Toby Goodwin, Craig Steele, Nathan Hayes, Clyde Parham. I could go on and on.