Gross production. It's basically "no player with his market share of sacks and tackles bla blah has ever become a pro bowler" and "no pro bowler has ever played at such a low snap count" but measures these things totally independent of each other.
So, in this case, correlation = causation, it's known and even acknowledged, yet it's disregarded in the analytics.
To call Tim Williams unproductive is a total lie, the numbers say he is one of the most efficient pass rushers to ever play college ball, and he has tape showing an incredibly explosive high motor and refined edge rusher to support the numbers. Also to bash his snap count is absurd, when you have a pass rusher of his caliber and the greatest front seven in college ball history, keep the legs fresh, let the others do the dirty work. Not to mention the tape showed a pretty decent run defender