Fair to say you don't change a winning team. But how about "tweaking" a winning team? Judging by recent tests and ODI's we've found a winning formula so you'd expect there to be little or no changes to the touring teams.
I think the ODI/T20 teams will remain standard as is format. But what about the tests? Well how much better could they be? Two key areas definitely do need some work. I'll firstly concentrate on the top order, in particular the openers. It's utterly fair to say they are not doing their job. Of the two, Hamish Rutherford is a work in progress and will be retained. I think in the West Indies he'll find the tracks to his liking. I personally don’t expect a 50 every time he bats, but if he can convert his starts to a 40 or 50 every four innings he'll be there for a little longer.
Peter Fulton on the other hand is on shaky ground. Sure his two centuries against England last year are keeping him in the team, but if we want to advance in world cricket (and the standings) he has to deliver some results in the West Indies. If not, he'll be replaced. It's an opportunity for NZC to develop the team should he fail for the future. So that rules Flynn, Papps, Redmond and Guptill out and leaves the star of this summer of Plunket Shield and one test cricketing opener Tom Latham in the frame.
I'm not asking big things from either Rutherford or Latham as a viable top order partnership. If they can manufacture 40 - 50 runs as a partnership it takes a little pressure off the remainder to follow. If one or both fire, then all the better.
The other key area is obviously the spinning option. Ish Sodhi is the incumbent, and still a work in progress. He has to go for both tours and will probably find himself in work at both venues. But if he fails to make a mark in the game at the top level?? So who is there biting at his heels? There are a number of options. The first is the possibility Todd Astle could make an appearance. Or getting Nathan McCullum transplanted from ODI/T20. He may not be a wicket taker, but can tie up an end. The only question is can he bowl 40+ overs in an innings (if needed to)? There are no other apparent successors.
So with that in mind, the Test Team for both tours. 15 Man sqaud.
Latham (to cover 1,2,3)
Brownlie (Cover 3,4,5)
Neesham (Cover Fourth Seamer/Allrounder)
Milne (Cover Pace Bowling)
New Zealand cricket currently has a dearth of riches to choose from, but for those riches to come through the current 11 need to be playing poorly. My own observation is that that’s not going to happen in the near future. There is balance, there is form, there is belief. And this team is a winning team. Tweak at your peril.