I'm not saying Smart is untouchable, but you'd have to get a very good player in return. You said we'd be fine defensively trading him. I'm saying he's more valuable on the D than AB.
Stevens wants guys who can play multiple positions. AB is a better shooter. Smart is very good at getting the ball moving once he's brought the ball up the floor. He also very good at getting the rebound and finding the open man down the court. Thats were he's better.
AB can guard two positions. Smart had done 1-5. But mostly 1-3 and how Stevens wants to switch on D Smart doesn't hurt you when a bigger player posts you up. And with IT, you can't have two guys who get posted easily.
You also have to know who you're trading for, one player may work better than the other. I'm just saying it isn't that easy. But I'm sure you'll say it is...
I disagree. Despite his athleticism, Bradley's size means that he can only guard point guards or similar size shooting guards, of which there aren't many in the league in reference to the latter. CJ McCollum and Victor Oladipo are the only two that I think of off the top of my head, right now.
And then offensively, Bradley can play as a shooting guard who comes off of picks, hand-offs, and shooting his pet shot off of the pick and roll, but that's about it, and having him play point guard is a recipe for disaster, lol

. What an odd team we have - a seven footer who can't rebound because of T-Rex arms in Nolynyk, a combo guard in Smart who has neither the passing, ball handling, shooting, or the ability to get the basket to play either backcourt position but transforms into an all star once a year when playing in OKC

, a good athlete who plays out of control and is an undersized 2 guard learning how to be a point guard in Rozier, a physically, albeit not athletically, imposing small forward who can't use his left hand, and can only score on straight right handed line drives, spotting up, and coming off of hand-offs, more of a 2 guard trapped in an undersized point guard's body who is a major defensive liability in Thomas, a rickety 29 year old former preps to pros player who takes more time to shoot a jumper than is needed to load and fire a musket, lol

, a tweener with a set shot in Jerebko, and James Young (need I say more about him, lol?

), and that's before factoring in any and all of the new guys. Ugh. I didn't put Hunter in there because we haven't seen nearly enough to make a judgement on him, imo.
You lost me with your reliance on "advanced statistics." Most of them are garbage. I've seen the laughably pillow-soft Kelly Olynyk try to play defense.
I'd happily move Smart for Westbrook, Okafor, Noel and basically anyone who can shoot the basketball. He isn't good enough on the other end to warrant otherwise.
While I agree with you in terms of advanced stats, none of those four players can shoot at all, lol.