Okay so I'd challenge you this way.
This is the exact same defense that they had last season except they've bought out Seids, and now they "have" Liles for an entire season. But otherwise, nothing has changed. Moreover, your best dman, whose play slipped as the year wore on, just got another year older. So I think this defense went from a non-playoff defense to at best status quo, possibly worse. Up front I like the forwards in that I think it's a playoff worthy forward group. Good, not great.
But I think what shows they can't possibly be a Cup contender is that even in 2011 you came in with a "nucleus". Bergy, Krejci, Horton, solid 4th line, reliable #1 dman and two quality goalies. Now your 3rd-4th lines are at best less proven but likely worse, and most importantly, you don't have a #1 or a #2 dman. When's the last time a team "won" knowing for certain they didn't have a #1 or #2 dman? The Bruins know that for sure. That's a tough spot. Nermind that the other two pairings aren't great shakes either...what's the last team to contend for a Cup who entered they year knowing they didn't have a #1 or #2 Dman?