I'd be very very in on Okoro.
Was a huge fan of him coming out of school (but I have a real soft spot for his archetype) and think developed into a pretty solid 3&D wing that can flex all the way down to the 4 because of his strength. Really is the perfect sort of guy to add to this core. And still just 23, so maybe can unlock a bit more of his game.
CLE defense is 2.9 points better with him on the floor this year. With a near even minutes split, which is pretty damn impressive considering the defensive talent on that squad. (2.9 points worse on O, but who's counting?).
Okoro is definitely interesting. I would be a bit concerned about trying to give him too much time as a 4 with his size, but he hits the corner three and is a defensive stud. The other question, of course, is how much money he's looking for in the offseason. We would have him as an RFA, but can we afford to keep him?