Smart's history here is less "overly prolific shooter" as someone who throws up a few ill-timed shots that look awful and get disproportionate attention, especially when the team is on the shorthanded side. Regardless of his role, Smart will shoot less next year simply because the Celtics are healthier (we hope).This is where I stand as well.
That said, I'm struck by the irony this choice may actually end up neutering Smart's greatest advantage. The man can absolutely defend four positions credibly, but I'm not sure that playoff-quality 1s are on that list.
As to defense, over the past few years, the top strategy for attacking the Celtics in the playoffs has been to attack Kemba or Kyrie or IT with switches. With Smart at the point, that vulnerability goes away.