It would be hard to make a trade work because of Rob's poison pill but this does work once Smart can be traded
Boston - Siakam
Toronto - Looney, Kuminga, Toscano-Anderson, Nesmith, R. Williams, Hernangomez
Golden St. - Smart
Raptors take on way too many players, but they could potentially move them elsewhere, but that complicates the trade even more. Now if GS would trade and Toronto would want Wiggins then it becomes a lot easier to work as Juan can go to GS and only Wiggins would need to go to Toronto