The trade was a win if:
1. There is actual general consensus among the top drafting GMs that there is little separation among the top 4 talents and that the ceilings of these players are comparable. In this case, Philly paid a possible future top 5 for the opportunity to draft a player who is more in a position of need. And, DA and CBS just pulled in a very nice asset if they believe Jackson/Tatum have as much star potential as Fultz.
Note: Had the Lakers just traded the #2 for the #3 and Sac '19 top 3 protected (let's take the Laker pick out as this would put the Lakers in position to tank for it), I think many here would be thinking the Lakers got something for nothing and would be praising the pick from the Lakers perspective.
2. Making this trade preserves Brooklyn '18 in an upcoming trade for George or Butler. IF the expected price was #1 plus Nets 18 (plus Crowder or Bradley), and they believe they can get the trade done using the Philly return plus a player, they have essentially kept Nets '18 by making the Philly trade.
3. They can trade for George or Butler without using both assets attained in the Philly trade. IF Danny can pull off a trade with Indy or Chicago using only the #3 plus other assets (not Brown or Nets 18) OR only the LAL/Sac pick plus other assets (not Brown or Nets 18), then I think the trade is a win.
4. The obvious: Even if you believe it's a bad trade on its surface, if the C's end up with the #2 pick in '18 (maybe along with another top 5), it's a huge win. The 'win' in this case doesn't sit so well with me as it's a roll of the dice (I'd rather have the sure thing if Fultz is indeed the real deal), but the protection on the Lakers pick actually makes it a surer bet to be a top pick than if totally unprotected (if you believe that Sac is destined to be Nets-like in 2019).