Like Denver, it's really hard to find any holes to fill for OKC. Despite being overall dominant last year, they were middle of the pack in rebounding (despite Hartenstein) and assist percentages. You saw these problems in the playoffs sometimes.
In this trade, they get help on both fronts. They get Goga, one of the most efficient rebounders in the league, from the Magic. Goga will help spell Chet and Hart. They will also probably need to move on from Hart at some point, maybe next summer, with their big cap hit coming.
And they get Tre Jones, a very steady orchestrator, from the Bulls. He will help keep the offense moving when SGA is on the bench, letting Caruso or Dort play off the ball.
Orlando gets a young wing in Joe to help with their shooting.
Bulls get Howard, a younger prospect too.
Go ahead and argue about picks...