Assuming LA and Brooklyn are contributing some amount of picks this trade works.
Portland would get some picks, Vanderbilt and Simmons as a flyer/ expiring contract.
LA adds defense and more playmaking
The Hawks add a reliable 3 and D wing in Grant, plus a good rotational defender in Thybulle. They could also swap out Grant and Thybulle for Ayton if they want to replace Capela.
Brooklyn fills in some of the roster gaps for cheap while waiting for a star to become available. This move would work if Mitchell becomes available too.