I think asking for anything more than what Derrick Williams did for us a few years ago is unrealistic. I see sort of like DW, a couple of great games off the bench, lots of inconsistency, not reliable as a starter but still a valuable bench player that can give some instant offense.
We're clearly built around Porzingis at 4 and Kanter/Willy at 5. Beasley is not a 3, he can't shoot from outside. He is best served being a 4 on the second unit.
Kanter
Beasley
Kuzminskas
Lee
Baker
That second unit will be able to score and share the ball.