This line of argument reminds me of Bernard Mandeville's suggestion that disasters at sea are actually a good thing because they create jobs for shipbuilders. You're basically saying that donating McDonagh led directly to us finishing in the bottom-3 in the league, but we're supposed to look at the sunny side, because we ended up with Galchenyuk. I admire the commitment to optimism. But any trade that unintentionally leads to a team being a bottom-feeder is a bad trade by definition.
Apart from that, this team still has a structural need for a quality top-4 defenceman. And we would be much better with one in the lineup. That's McDonagh. So Galy aside, that trade is still hurting us.
I'll say this much: under Bob Gainey, the Habs were not afraid to make bold moves. He went out and got Kovalev. He bet the franchise on the controversial Price pick. When he saw a chance to contend, he dealt away picks like crazy to add players he thought would address team weaknesses. When that didn't work, he firebombed the entire roster AND the entire coaching staffs at both NHL and AHL levels in what I still think represents the single most radical act of GMing in living memory. We can complain that he made too many errors - which he did - but he hardly a "stand pat" guy.
MB has stood pat so far, but I don't think anyone expected us to contend by this season. What we need to see next year is clear progress in addressing longstanding weaknesses rather than nibbling at the edges. Bourque and Gio had better be gone, with some sort of upgrade in the place of at least one of them. We also need an upgrade at D (and if that means moving Markov, so be it). Remember that we did see progress last season, so it would have been odd for MB to make bold moves after that. This year has been more flatlining combined with disturbing indications that last year's late-season meltdown was not a fluke but a symptom. He has more info now. Time to crank it up.