The Dallas-Memphis trade would be separate.
Washington pushes to make Beal happy and stay while also collecting draft assets to a future rebuild if Beal leaves( maybe you could throw in another player for them but the money wouldnt match).
Dallas Finally gets a good C that is a clear upgrade over Powell and WCS and only giving up 2 2nds is a very good price.
Memphis gets another good potential guy while also getting another 2 picks for the 2022 draft.