I think this deal in large part has to be seen in light of the fact that there was no way we were going to go into the season with Edmundson, Savard and Wideman as our top-3 on defense. Hughes was crystal clear that if Petry is dealt, a veteran defenseman would have to be brought in. Matheson kind of fits the profile as he substitutes for the part of Petry's game that was most valuable to us, namely puck-moving from the blueline.
That said, this deal leaves our defense pairings unbalanced as Matheson is a lefty. Our best defensive defenseman is suddenly without a suitable partner. Would someone be surprised if we go after Stralman on a 1-year deal if we manage to clear the cap?
As regards to cap space, this doesn't help us much in the short term, although it allowed us to immediately re-sign Pitlick. I think the expectation here is that if Matheson performs as well as he did in Pittsburgh, we should have no problem moving his contract later on if we wish to.
Poehling I think was not very highly valued after last season. In fact, with Suzuki, Dvorak, Dach and Evans down the middle, and a glut of wingers, he was far from certain to crack the lineup. It seems last year was his last chance to demonstrate he could be a useful player in Montreal and he did not pass the test.
I fully expect further moves during this off-season. I'm pretty confident Anderson will be traded. If the Dubois trade materializes, I expect one of Dvorak/Dach to be gone as well.