to summarize: the best thing about Creevy and Bismarck is they're flankers who also insure hooker skills. Again to make this short, Creevy's workrate this entire int'l season is what has made him the best in the world, that and the fact Bismarck hasn't had the best form consistently.
About NZ and their front row, it's cultural:
they haven't had a dominant front row since Hayman left them. But unlike France who until recently had the best scrum in the world, that front row is made up of guys who can offload and have velvet skill whilst holding up ok in the scrum, and it's working out, so far. NZ's second unit is a problem: when's the last time before 2014 NZ conceded a *penalty try* while being 8 vs 8 ???...(2009 in Italy it should've happened, though).
In a perfect world, NZ should be fielding Carl Hayman with Owen Franks off the bench, but the world Rugby chessboard has changed and players go overseas and lead epic careers elsewhere now too and the NZRU won't pick those anymore.
I do know for a fact though that although "no scrum no win" is wrong today (as just one e.g. I mention one word: 'Wallabies') - the scrum in itself can be the difference maker in having a higher or lower score after 80min than your opponent. It's not like NZ have a choice (well actually, maybe should've picked Hayman all those years...), but hopefully for them this doesn't come and bite them in the butt at the RWC in a KO game.