It was never going to take long for Monty to start mixing up the lines, and these combos are worth a look. I had thought that Poitras had better chemistry with Freddy than Geekie, but I can see the logic of Geekie and Marchand as quite complimentary wingers, while Coyle centres a heavier line that will suit his more direct, attack-the-net style.
DeBrusk and Pasta have very little history playing together, but I think that's largely because there are similarities to what they bring to the table so it's always made more sense to disperse those skill sets. Perhaps though that no longer applies. They're clearly the team's two best offensive talents now, with offseason losses and Marchy aging, so why not throw them together and see what they can do. I'm still not sold on Zacha as a center - he's a talented player but I see him more as a complimentary player than one who can really anchor a line - but it's early days and there's nothing for it at this point but to stick with him and see how it pans out.
I think generating 5v5 offense is going to be a battle all season, or at least until the trade deadline, so the coach is going to have his work cut out both to find what works best in a given situation, and to know when to persevere with a particular combo and when to try something else. Just how well the Bruins go this season is going to rest on that more than anything else.