Any one of these guys (Bender, Murray, Heild, Simmonds, Dunn,...) could end up being the best player in the draft. So to say that Brown could end up being the best player in the draft while true is not really saying all that much.
Drafting is a crap shoot. You could have put the top 5 or 6 names in a hat a picked them out randomly and had an equal chance of the picks aligning with the future contribution of the players.
Brown is a fine pick at #3. The talent and athletic ability is great as is the case with other players but Brown seems to have a real edge to him, a real competitive drive that to me sets him apart a little bit from the others. Talent may continue to develop or may plateau but that drive will always be there. That is why I think Brown was the best bet at #3.