So you're saying thought the trade would essentially be 3 first rounders for future consideration, with that future consideration being the Knights taking Dustin Brown? Lombardi may be many things, but is not that dumb. I'm sure he's aware of how relatively weak their pipeline is, and how little top-flight talent they have outside of Kopitar, Doughty, and Quick. First rounds are cash money to flagging franchises, and for a franchise that has won 1 playoff game in 3 years, you would have to think that their window is essentially closed on this core.
No matter how bad Dustin Brown's contract is, it would make much more sense for the club to buy out his contract versus paying somebody to take it off of them for that amount.
Plus you get to keep the guy we would have taken in the draft without the trade!