Sometimes these reclamation moves pan out, most of the time they don't.
My guess is Dach would be the same Dach now as he has been these past years in Chicago and the Hawks figured that to be the case. So they turned Dach into a decently high pick and grabbed a guy they liked. The reasoning for the move is sound.
Habs are in throwing dart mode and they turned a good defensive D man into a realistic shot at a top 6C given how they viewed Dach.
Is Dach looking like a C ? Not so much at the moment. As a Habs fan I have to say that if this is who Dach is long term, but on the wing , I am thrilled to have him. Now I get sometimes guys do well for a while after a trade, and then drop back, but he didn't take off until he got to the first line. I'm hoping he's the real deal, but time will tell. So far so good.
I think all 3 teams did just fine.