I agree that there are ways to reduce Ertz's carries, but the threat of QB run game (especially read option which he seems very good at) is a reason why some of the RB runs are so effective. Also, I've been very impressed with Ertz's ability to make people miss and his burst. He's not especially fast, but he's a very effective runner, shoulder injury or no. Its not like a QB with a shoulder injury is some new development with a Snyder QB.