Serious question?... Santner - what is he in the team for?
He is a key part of the white ball side (#3 ranking T20 bowler, #31 ranking ODI bowler, 10-34-2 in WC semi final win, useful white ball hitting at #7 / #8), and Kane is his domestic captain. When he made the test side it was as a batting allrounder at #7, in a playing XI with 4 quicks. The success of de Grandhomme means Santner now bats at #8 and NZ have relied on Wagner to take the majority of 3rd / 4th innings wickets in home conditions. Has worked OK at times - last month a Santner century and 3 top order wickets probably made the difference between a win and a draw.
In the sub-continent the NZ selectors pick wicket-taking spinners, but in NZ and Aust conditions they prefer an extra batting all-rounder that can bowl some overs of part-time spin.
Many Kiwi posters here would prefer a 4th specialist bowler instead of Santner in the text XI.