I don't see how having Galchenyuk on the team can contribute to most important task: the rebuild.
The priority is to maximize trade value at the deadline of the players we'd like to deal, as we're not making any noise in the playoffs this year, and to maximize the development of young players.
Forwards:
Pacioretty-DD-Bourque (minutes as easy as last year's)
Plekanec-Eller-Cole
Armstrong-Gomez-Gionta
Prust-Noke-Moen
Spares and injury replacements: White, Leblanc
The above is a forward lineup that maximizes any potential trade value for Bourque and Armstrong. It also allows Eller to take the next step up. It also puts Gomez in a position to succeed, meaning we could conceivably extract a 3rd rounder from him at the end of the year if he bounces back and gets 30 points as the 3rd line center. I remind everyone that Gomez has a cap hit exceeding his salary by 3 million dollar next year.
Defense:
Markov-Subban
Kaberle-Gorges
Bouillon-Emelin
spares: Diaz, Weber
This is a defensive lineup that puts Andrei Markov in a protective position to succeed, as he will be covered by the best defensemen on the team, giving him room to grow back. Kaberle-Gorges is a good pairing at both ends of the ice, and they compensate for each other's weaknesses, meaning we could flip Kaberle for a 1st rounder. Bouillon-Emelin can be the shutdown pairing.