I do think that a team's philosophy must be consistent with the kind of players it has, but that doesn't mean a team can't produce any kind of players it wants.
New Zealand is flush with all-rounders who bowl good some good fastish medium-pace. This makes their batting lineup considerably longer than other teams (which the South Africans discovered after letting their guard down after pushing NZ to 6 or 7 down only to see them double their score before being all out.) But they don't really have any batsmen who can dominate a side. Astle and Fleming aren't the same as they used to be. They don't have a Hayden, but the way they play, they don't need it. They don't go out expecting a century from anyone, but expect everyone to bat with a solid 40 and they always seem to end up at around 350-400.
I think it is a wise decision for them to become more attacking, as Test cricket has become increasingly attacking. No New Zealand batsman will give bowlers of any class nightmares, but they are all gritty players. Their historically good touring record is evidence of this. Likewise, no New Zealand bowlers will give batsmen of any class nightmares (even Shane Bond is now reduced to medium-pace apparently, although hopefully that's only until he regains full fitness) but they bowl smartly and probe away until they take wickets. Also Fleming's captaincy can't be discounted.
The only thing New Zealand really lacks is a high-quality spinner. But really how many teams have one? Only Australia, Sri Lanka and India come to mind. (Pakistan do have Mushtaq, but he seems a spent force, and Kaneria is too inexperienced to say at this juncture). This means the other seven test teams really have no spinner of note, but that doesn't mean New Zealand shouldn't try. I think Vettori is highly overrated, and is in the team more for his batting than his harmless bowling. A bowler with a test average of 37.8 is not good, and I don't care what anyone will say about New Zealand pitches not being conducive to spin; he doesn't bowl well on spin-friendly surfaces either. That seems to be the last piece of the puzzle as far as New Zealand are concerned.
One weakness that New Zealand have is quick deliveries which swing, as Akhtar and Sami made clear. (South Africa didn't do as well as Pakistan because Ntini has good pace but he bowls too straight, and in my opinion underuses his effective cutters, and Pollock gets prodigious swing but not enough pace. Nel - who knows what he'll bowl next!)
To be honest, I've typed too much and I've forgotten my main point so I'll stop here!