Which is one reason why they may choose to keep Butler over Valentine, as one can argue the importance of having a more versatile player who is able to line up in different spots and provide something of an interior pass rush, as opposed to just another big bodied run stuffer.
Butler played in all 19 games, recording 4 total sacks, at least two which came in very important spots (AFCDG and AFCCG). Ultimately, I’d prefer keeping both, but it’s certainly possible that Valentine is not close to being the lock that most think he is.