This would be my alignment for the first game. I would give Allen and Monahan more time to recover from their injuries, and yep, I would put Ylonen on the first with Suzuki and Caufield in order to let him prove his worth; move Gallagher and Armia to the 4th and give Evans the third line since Dvorak has yet to prove he's ready to compete for lots of playing time.
This brings in the younger player at the top for the first 5 to 10 games. Let them play it out. If they fail, who cares Habs get another run for a top 5 player, but at least they gave the younger guys time to play and see if they are worthy of keeping them around. So many 3rd and 4th liners have gone elsewhere and proven their skills on top 2 lines, why not try it out here.. Now..
This gives Dvorak two NHL experienced players, and because of their age they will have time to recuperate, yet still be able to play if the other third lines are wasted.
I go for the Montembeault/DeSmith duo for now, rest up Allen in case they can trade him.
I'm only worried some other teams would come in and take Primeau, but given his current track record, I'm not sure they would.