The Montreal Canadiens top six is pretty well set or not far from it, but the bottom six, especially the third line that's a different story.
But as any hockey follower is well aware of, for a team to be successful all four lines need to perform. That is precisely why the third line's formation will be important, as a complement to the top six. There are a handful of options for the third line, but there are three guys that stand out as a solid trio.
Christian Dvorak is a responsible two-way centre, who is a meat and potatoes player for all intents and purposes. He gets the job done with smart defensive reads and strong play in the faceoff dot. He isn't going to provide much offensively, but he isn't going to hurt the defensively, which is more or less what you want for your bottom two lines.
Joel Armia is a hound both with and without the puck, without it, he is relentless on the forecheck and leans on opponents to retrieve it. With the puck, he is hard to strip it from and wears down the defenseman in the attacking zone. Armia has strong puck skills, but he can be very hot and cold, scoring two goals in a game, but none over the next 10, which is why he is suitable in a lesser role.
Brendan Gallagher goes hard every shift, causing havoc on the backcheck - forcing turnovers with a dogged effort and smart defensive stick. On the forecheck, he makes smart routes to the net and his undying motor creates problems for opposing defenders. Offensively, he battles for loose pucks, shoots every chance he gets and always sets up shop around the opposition' crease.
Annoying but hard to play against
One thing that can be sure about this version of the third line is that they are all difficult to play against. Each one challenges the opposition differently, but cohesively they create time for each other. They contain the puck and bleed the clock, but never make unnecessary plays.
Offensively they could always produce a little bit more and if they can form some chemistry that may not be a crazy thought. They each have some goal-scoring touch, Gallagher primarily and Armia, while Dvorak can chip in here and there. If all things go right, this could be a painful line to play against and one that Martin St. Louis loves to deploy, to create energy and wear down the opponent's.