Gally is tied for 64th in goals and 129th in pts for forwards
My math tells me there's 180 'Top 6' players in the NHL so I'm going to say he's either a below average goal scoring 1st liner or an above average all around 2nd liner but no doubt a Top 6 especially with the intangibles he brings with his energy and going hard to the net and being responsible defensively
Having said that I'd like to see Sekac tried with Chucky as he has more skill and Gally moved back with Pleks
I'd like to see Parenteau tried wtih pacioretty and Galchenyuk actually, what that line needs is one of those shifty little guys who will get to high chance scoring areas and be ready to strike. PA isn't a known sniper mind you, but he is a very skilled offensive guy who could definitely play that role on a line.
Gallagher, as great as he is, isn't THAT efficient at taking advantage of the open space afforded to him from playing with Pacioretty and Galchenyuk, it's not a knock on him necessarily...where he thrives is forcing his way through traffic and coming in through the muck to get scoring chances.
That's why he works so well on any line he plays on, he sort of does his own thing out there (not that he's a puck hog in a bad way) and doesn't really need/readily take advantage of that open space.
Pacioretty-Galchenyuk-Parenteau
Desharnais-Plekx-Gallagher
Sekac-Eller-Prust
Bournival-Malhotra-Weise
Yes the 2nd line is small, but the 1st and 3rd lines are both big and all 3 of the guys on the 2nd line play bigger than their size.