My man he doesn’t have the ball handling or play making skills to play the position.
He is solidly a PF.
In fact, I am not sure where at all you are getting he is a SF when all of his pre season minutes have come with him playing the 4.
Lineup doesn't need any ball handling/playmaking when you have Garland and Mitchell and even Mobley handling the ball. It's irrelevant. He needs to attack closeouts with momentum(to create breakdowns instead of doing so with ball handling and playmaking).That's it.
Okoro can handle the ball probably more than he showed and most likely better than Diakite, but even then, JBB didn't want him handling the ball. Only to space the floor for Garland and knock down open shots.
For him to play his position he needs to guard that position, and I think he can guard it better than you think. His value defensively is going to come from challenging shots more effectively than your average SF on perimeter as well as inside. He doesn't even need to lock down the perimeter because you have Mobley and Allen effectively coming to help whenever there is any breakdown.
The big idea and strength is that you have Mobley, Allen and potentially a specific scheme that can make everything work. Two shot blockers and one super intelligent, skillful help defender and one who understands rotations and reacts to every kink the offense throws at him to exactly counter any defensive breakdowns. Markannen's strength defensively was not his lateral quickness -- it was his size, ability to contest both on the perimeter and inside as well as rebound well for a wing. He was not a good rebounder, but he is better than average for a SF I suppose.
No matter what, Cavs will be switching a lot or at least find themselves defending players that are not their own matchup. Switching scheme, zone, whatever be the reason. That alone helps him in that regard. You want to have size when you switch (defending the post, securing the DREB, etc), and Diakite provides that.
Offensively, like I said, he should be able to knock down open shots, particularly from the corners, attack closeouts and finish well, and crash the OREBS. A 3 man wrecking crew of Mobley, Allen and Diakite crashing the boards after a shot by Garland/Mitchell is an insane weapon. You are not only allowing them to shoot more shots and making this potential offense even more devastating, but you are also limiting fast break opportunities in a major way. And this team's half court defense should be special.
This post is not directed specifically at Diakite. It's the idea of his archetype or rather what he can be and his usefulness or the general idea of it to this team. Big wing is the way to go and this is why I really wanted Eason.