Again, trading for Karlsson wasn't the mistake. Signing him was. That's why they had to let go so many of their vets and that's why they went from contender to laughing matter in essentially no time.
Nobody wants Labanc...there are lots of reports about SJ trying to trade Labanc...it never happened. For a good reason. Great skills but no hockey sense at all. Also, SJ wouldn't have traded three roster players for one...that wasn't gonna happen. If Labanc was included, it would have been for DeMelo. They also wouldn't have included a top6 forward in the Karlsson deal so Hertl, I'm 100% sure, was never even part of the conversations between the teams. Even if Dorion mentioned Hertl, Wilson would have hung up his phone immediately. Wilson was trying to land Karlsson to win cups, not to drift sidewards and improve his defense just to weaken his forward group.