The problems:
The Nets just have too many mouths to feed. Royce & Dorian are redundant. They just drafted Dariq Whitehead. They signed Darius Bazley & Trendon Watford. Ben Simmons is coming back. Mikal & Cam Johnson still exist. Just gotta get rid of someone so the others can get their well-deserved minutes.
The Cavs are too talented to wait for Isaac Okoro to develop. They also don't have any 3&D wings - all their wings can either score or defend.
The Wizards don't have enough young players to build around, just yet. They also have a boatload of second-rounders.
The solutions:
Nets offload Royce O'Neale's expiring contract, receive two more second-rounders.
Cavs add a starting SF who happens to be good friends (and former teammates) with Donovan Mitchell)
Wizards get a former top-5 pick for cheap. Okoro's only 22 and if that jumper ever gets going, he'll be tremendous.