I see it with both Tua and Brissett. Neither one has gotten good RESULTS. Neither one has had much opportunity for success.
Fact of the matter is this team, after seeing both Tannehill and Rosen (in his 5 games) not be able to overcome all ills on a team, decided to do the exact same thing with Tua.
Maybe they couldn't have magically improved the line, but the team had ample opportunity to get a better running back to take pressure off the passing game, and that three years in coming off a ten win season the best thing they can do is "co-coordinators" from nowhere is terrible.