While this is an old question and drafting the best player available seems to be the consensus answer, I think it's not that simple. The most famous case probably was Houston drafting Olajuwon for need instead of Michael Jordan. Yeah, it definitely seems "talent" is the right choice, but you would replace any player on your roster for MJ, it's a no brainer.
If your starting SG is Afflalo of course you draft MJ. Replacing an average player for a superstar is easy, ¿But what if the player whose position you are drafting is above average, and the player you are drafting doesn't have the Lebron or Carmelo hype? What about when you have prospects like Vucevic and Harris and the best player available is Noel? We don't know what their ceiling is as with MJ or LeBron, so I guess is not that easy.
Harris and Vucevic could turn into above average NBA big men, but probably they will never be Allstars. If you knew Noel has AllStar potential then yeah, duplicate talent, but again, there is no consensus on that either. Meanwhile Orlando desperately needs to get some guards and Burke seems to be the best guard available, but just the 4th or 5th best player in the draft.
Maybe it's easier to explain it with numbers: In a scale of 1 to 10, 10 being Michael Jordan, 9 an allstar, 8 a great role player, 7 above average role player, 6 average role player, 1 being Reece Gaines, and 0 being Chris Duhon:
A) If you think Harris and Vuc will be able to become a 7 , Noel a 8 and Burke a 7, I would draft Burke. Three "7" complementary players are better than three slightly better players playing the same position. Orlando would have killed for a PG less talented than Marcin Gortat but more talented than Chris Duhon. Having a talented player playing only 10 mins a game doesn't help much, and in trades the team with the best player usually doesn't get fair value in return.
B) if you think Harris and Vuc will be able to become a 7 , Noel a 9 and Burke a 7 then of course you draft Noel, you don't let a superstar go just because of good role players.
C) If you think Harris and Vuc will be able to become a 6, Noel a 8 and Burke a 7, then again you draft Noel, the talent gap is just too big.
So who should we draft? You tell me, I'm just a guy writing stuff.
NOTE: This post assumes Noel health is OK, that Noel is better than Burke and does not take into account trading down scenarios (we don't know where are we picking yet).