Michalek-Turris-Alfredsson, the general purpose line. When the Sens control the matchup this goes against the other side's best players. They play fairly low event hockey about even and their primary matchup purpose is to draw the other side's top defensive pairing away from other units. As a trio they have been good for about 50% puck possession and even goal differential in what looks like reasonably hard minutes. On even strength, Turris is a career ~8% shooter (below average) and shoots a fairly average 7.87 shots per minute with Alfredsson at a fairly anemic rate with these linemates making him a below average scoring threat (~0.65 goals per 60 projection). Alfredsson is realistically around 10% ES shooter, and has declined to 5.47 shots per hour with Turris and is likewise a below average scoring threat these days. The bigger threat is Michalak, another 10% converter with a Pacioretty-esque 12.1 shots per hour so far with Turris, which makes him a goal scoring threat to take seriously. It appears he is the guy this line will look to feed for goals.
Overall this a mid-level offensive threat with a decent two-way game, talent wise about par with many 2nd lines on playoff teams. I'd think Plekanec-Gionta will likely be squaring off against them both on the road and at home as neither side will want to expose their less reliable units to these veterans.
Latendresse-Zibanejad-Silfverberg. A rookie scoring unit, they play heavily sheltered zone start minutes and play as the team's primary offensive weapon on even strength. This line seems to have the most leave to take some offensive risks, and is specifically deployed in the offensive zone and against bottom six players when Maclean controls the matchups to keep them on offense and away from playing defense. Neither Zibanejad nor Silfverberg have much of a track record in the NHL, in limited minutes Silfverberg has been a high volume shooter with poor conversion, and Zibanejad a middling shooter with fairly comically bad shooting percentage. Silfverberg was .85 PPG in the AHL this year and Z .48 on the same team.
The line as a unit has not spent enough time together for any kind of meaningful track record to be established, but they have been negative possession (48% in their short time together). Zibanejad and Silfverberg have spent more time together, as a sheltered offensive unit (53.5% shot differential) and have been the Senator's most productive ES scorers. Latendresse is the Senator's best converter with a career 13% rate and gets a fairly average amount of shots making him the team's best goalscoring threat after Michalak, while Silfverberg has been an average goal scorer with up side to potentially be a good one if he can make good on his more of his shots.
As the Senator's 2nd best offensive line, I'd expect Galchenyuk-Eller seem like likely candidates to take them on for this series. Expect OTT to try and get them out against Boullion on the Habs 3rd period as their preferred matchup as OTT tries to squeeze out what scoring they can get.
Smith-Neil is the shutdown duo, with Greening joining them. Their job is essentially to make sure nothing happens on their shift, a job they do decently well at. They run a 54.2% shot ratio in a secondary matchup role, which is pretty impressive for this kind of line. But this is zero scoring event hockey they play, with Smith and Neil ineffective at turning possession into goals while the opposition rarely converts on their goaltender behind them. Neil gets 8.4 shots per hour, Smith 7.9 and both have a poor career shooting percentage, (7.7% and 8.2% respectively). They are very much below average scoring threats. Greening who joins them gets less shots, but his an average shooter so works out to be about equivalent in goal scoring.
Overall this is a good defensive grind line that won't contribute to the offense to any significant degree. Their primary matchup is probably going to be Pacioretty-Desharnais this series, as Ottawa attempts to blunt the Habs' 1st scoring line.
Conacher-Pageau-Condra. Depth scoring 4th line. Pageau has basically no professional track record except as a half a point per game player in the AHL this year, but he's done pretty well in his 9 game callup this year. He's such an unknown at this point that's I'd treat him as a wild card. My first impression would be to dismiss a not particularly distinguished AHL scorer as a player in the NHL, but Brendan Gallagher was the same, so anything is possible. Conacher gets dumped down the depth chart by Michalak and Latendresse both being in the lineup, he's been a decent scoring threat in his rookie year but I don't think he's that much of a danger on his own. Condra is basically the definition of a non-threat on offense. This might be a more threatening unit to a team with worse forward depth but Montreal can always pull out Halpern or Eller.
Every line here has done its part at maintaining their team in the black, but one has to think their lack of offensive talent compared to what the Habs can bring to the table should be a definite point in the Habs favour. As a unit they play a tight defensive game but they look like they will struggle to score on even strength if they need a goal. They have a decent all-round line, a offensive exploitive rookie unit, a defensive specialist line and a wild card 4th line.
Philips may or may not be injured for this series. If he is expect Gryba to pair with Cowen for a defensive specialist pair while Gonchar and Wierioch form an offensive duo.
Methot-Karlsson is the bizarro land version of Gorges-Subban. Approximately equivalent on puck possession and talent, but this pair is geared towards being offensive support in heavy minutes rather than the shutdown pair the Habs favour. A 60% corsi rating, about 56% fenwick and 54% shot ratio has been their trend, indicating a elite puck possession which should translate to good goal differential.
Cowen-Gonchar is a pretty solid pairing in their own right, ~53% corsi in limited minutes since Cowen's return. GIven their track record from the season before, they seem to be a bell-weather unit for the Sens, as a middle pairing they will go as the team goes. Gryba has been something of a blackhole for the Sens, so expect a much weaker pairing if he draws in.
Weirioch has mainly played with Gonchar as a offensive specialist pairing, that has been strong on puck control in sheltered minutes. Philips is fairly non-descript as a Sens defenseman, generally used more on defense. Apparently Gryba is drawing in for Wierioch to play with Philips on the third pairing. Expect them to be used as a defensive zone third pair. Gryba is a black hole on possession, but he's big and good for the PK in the Sens eyes so he draws in for the offensively focused Wierioch.