The thing here is I think the Bruins are tougher... but Bruins' tough players are more important hockey players than Rangers' tough players.
I'll explain myself.
Chara, Lucic, Boychuk, Horton and these guys, are badly hurting their team if they spend 5 minutes in the penalty box. Their fighters are those guys you want to see play 16-18 minutes a game, or even 25 minutes for Chara.
Rangers' fighters are Mike Rupp (4th line guy), Brandon Prust
(also a 4th line player), Stu Bickel
(3rd pair defenseman) and then you have the guys like Dubinsky and Callahan who play tough.