I'm going with the OP's original question which sounds like all 3 picks. The short answer to that one is no. I don't see how we aren't going to end up with a couple of lottery picks. They have not cap room this year, so their best player next year will be Thaddeus Young. In the meantime, a lot of the teams with injuries or who just played below potential (eg Indy, Minnesota, Charlotte) will overtake them. We are one injury away from a top 10 Nets pick in 2016.
There are a ton of FAs in 2016, but also a ton of teams in hot cities that have both cap room and a future. I guess the Nets could, theoretically, sign two top guys with the hope of winning it all in 16, but if you're a true star, why not go to Miami, NY or LA (either LA) if you want the cool city? All of those teams have some or all of their draft picks in the future. The Nets only have Atlanta's this year and ours in 2017 (assuming we switch). Also, as good as the crop in 16 is, the best players are already likely spoken for. Durant likely goes to DC, LeBron stays in Cleveland, Love goes west.
Last thought: i would have to get the data to prove it, but my feeling is that draft picks are overvalued the most as we get closer to the draft. The media hypes up the draftees, scouts have a chance to salivate, coaches and fans begin to think "what if," etc. is Thon Maker the next Garnett? Maybe. Or maybe he's just the guy who is like the last guy who is the next Garnett.
One of the things I love about Ainge is his seeming ability to evaluate his team without emotions. Put a hoodie on him and call him Belichick. I think he could get a lot more than one player by waiting. Patience has proven to be a virtue.
Having said that, if the OP meant one Brooklyn draft pick and this year for a top 3, I'd do it.
Mike