Stanley Johnson and the Detroit Pistons are a match made in heaven. And apparently, Stan Van Gundy likes the fit so much that he passed over Justise Winslow, a small forward who was surprisingly available at No. 8, and picked Johnson anyway.
Detroit is extremely thin at small forward. When Detroit lost last season, especially during the post-Smith era when the team occasionally looked competent, defense was usually the culprit. They also could really use another scorer on the wing, especially projecting their current core out long term.
Johnson is a small forward, so that's good.