Noel wasn't a bad pick. Even Okafor wasn't terrible though it seems they failed on the character part of scouting with that one. The problem was more that, due to a combination of slightly bad luck (not drafting higher in most of the tank years) and choosing the BPA regardless of position, they wound up with so many square pegs, and then between Hinkie's bad relationships with other teams and the subsequent front office mess they couldn't get any trade return either.
Okafor would probably look real nice on this team right now as a back-up, given all the money you'd also have to spend w/ no Horford.
Of course they also had a bit of good luck with Joel dropping to them, but then again, they probably wanted Wiggins themselves at the time.
The real fun "what-if" to ponder is, would Hinkie have wanted Fultz? That's still really the original sin of this era, as neither the Butler nor the Harris trades happen if he'd been a star (or even, perhaps, if we'd just taken Tatum, though I don't think we would have gotten him anyway).