I dont think we have anything of value to get to top 5, let alone top 3.
And I like Nerlens Noel, but IMO if we;re going to trade up for another big man, we trade up for the Maryland dude Alex Len. He's not as explosive, but he has similar defensive instincts. He's longer too. He is super raw like Fab though, but hey there's a ton of potential and a bit more size in there.
Speaking of draft picks, we might be in range to get Archie Gooodwin (if he leaves). This dude can get to the rim, man. He's still a work in progress but the potential is oozing. Decent shooting, which he can improve. Still needs to work on defense but not for lack of effort and he also has the tools.