Phins have many paths they could take. If they think Sewell is head and shoulders better than the rest of the tackle class, I don't think it's unreasonable to take him. #1 priority is keeping Tua upright and giving him a clean pocket. The o-line did a good job of keeping him upright, but not so much on giving him a clean pocket. Not to mention run blocking needs significant improvement, which would also help Tua. More help is needed on the line, whether it's a tackle, and moving Hunt to guard or it's another guard and maybe a center. It doesn't need to be Sewell, of course, it will all depend on the opportunity cost.