I feel Grant is the most realistic target that can be made involving Kemba as Pistons could go the Thunder or Rockets route. I also feel the right trade could make the C's a top 2 seed if they do get Fournier back and accept paying the tax. I'd try
Kemba, Edwards, GW, 2021 1st, 2023 1st, 2021 2nd and two future seconds
to Pistons for
Grant, Joseph, and Plum
Pay Fournier up to 18 per.
That gives you the lineup of
Smart, JB, JT, JG, Plum
Main Bench
Pritchard, Fournier, Nesmith, TT, TL
Deep bench
Yam, Joe, Langford, Parker
That is a team I feel you pay the tax for.