I believe Poole is the best shooting guard for the cost and he is versatile in the fact he can play Point Guard just as well.

If Pistons can't find a good PF like Kevin Durant or Sabonis or Zion (Risky though) then I figure Poole is the best option.

James Harden is another good option. Kyrie possibly but you would likely have to overpay him.

Malik Beasley and Schroder would be resigned.