This is a site that likes to put together "complicate stats" just to be different.
If you follow up on that article and look at the "stats" they provide on their site it shows that the left tackle (Shelton) is way above average. So they can't have it both ways.
http://www.footballoutsiders.com/stats/ol.php
Look halfway down, where they show the left tackle "stats" and then the average. They have Shelton with a 4.80 and ranked 9th in the league. the average LT is 4.28, what ever that means.
Again, stats, and BS. I am one who supported getting Shelton in the past but I have seen Miami a few times already this year and he's pretty much been pretty bad. Lot's of talent, no drive or desire. Too bad, with the right motivation, and no I don't know what it is, he had all the ability.