It's a little bit of an urban myth that he is one-dimensional player. Due to ridiculous depth on that Alabama front, he didn't need to play 3 downs a lot but at times he did - this shows through TFL numbers if you didn't watch too many games.
In roughly half the number of snaps played, he has just 1.5 sacks less than Garrett but the most extraordinary thing about Williams is his effectiveness. For his career, he managed to get to QB on 25% of passing plays and that number in 2015 was 28% +. This is unheard of, he was in a QB's face once in less than 4 snaps. College average is about 10%.
Even if he was one dimensional player, with those numbers I honestly couldn't care less.