Exactly who do you want on your team?
For starters, someone who actually has the physical and athletic ability to actually play in the NBA.
In terms of a specific recommendation for power forward? Aaron Gordon. I also was pushing for the acquisition of Julius Randle when there were reports in the offseason that the Suns were interested in him. Same goes for Thaddeus Young.
It is also no secret that I wanted Brandon Clarke at 11 in the 2019 draft and would even have been okay with him at 6, though I considered him a reach at 6. I would have also been okay with Jaxson Hayes at 6. Clarke has a PER of 22.39, Hayes has a PER of 18.40. Cam Johnson, by contrast, has a PER of 11.87. Admittedly, in terms of defensive win share rating, Cam Johnson and Brandon Clarke are ranked right next to each other at 241 and 242 (Hayes is at 215), so perhaps Clarke isn't the defender I thought he would be, though he still has more natural physical ability to develop as a defender than Cam has.
BTW, Saric is ranked #304 in the NBA in defensive rating.
Ayton is our only Top 50 defender, coming in at #20. Rubio is at #63, and Bridges is at #96. Oubre is #175. Booker is #191. Kaminsky was #231. Carter is #251. Tyler Johnson is #272. Baynes is #290. Diallo is #396. Ty Jerome is #463.
I think this clears up why Jerome, Diallo, Carter (whose defense isn't as good as we thought) and Tyler Johnson are largely glued to the end of the bench, though it doesn't explain why Baynes nonetheless gets starts over Ayton.