If the goal is an 8 man rotation it's very difficult to mess with any players except for 7 and 8 and keep the rest of the core intact. That's why this trade seems so strange, it seems like a lot to give up for a player that's not a household name.
What is Derrick White though? He is a productive, low usage, ball mover that has a keen sense for finding seams in the defense and exploiting them. Defensively he is a stout player that commands his space and still takes opportunities for crafty off ball steals and blocks.
His on court presence and demeanor reminds me of Klay Thompson with way worse 3 point shooting but better passing. They both seem to not be the most athletic players but they are capable of using their size and length effectively on offense to create separation and on defense to bottle up faster and more explosive players that they're matched up with.
IMO Derrick White is now our 5th best player but it's closer to say he's 3A 3B 3C with Smart and Robert Williams III. Stevens has now locked in those 3 spots for years on fair contracts, promising continuity in what has been a chaotic roster construction in the J's era. Really happy with the deal.