Perhaps, but TB also played a heavier game against the Bruins. They out-hit us and man-handled us.
I don't think of this year's Bruins as a particularly heavy team. Lots of players whose identity is not "heavy" - DeBrusk, Marchand, Pasta, Krug, Grizz, MoJo, Kreijci, Heinen. But some of these guys can lay the body when they need to. Some players bring a notably heavy game: Carlo, McAvoy, Backes, Coyle, 4th line. Maybe Chara (but not quite the monster he used to).
So I see the Bruins as more of a hybrid. Their identity isn't "heavy" but they can accentuate heaviness if they need to. They're versatile. They're not a 1 ton truck; maybe a half-ton truck? They can zip through traffic, but they can also do some heavy lifting when they need to. And that's the kind of team you need to be successful in today's NHL.