I'd better be careful here but I can't see a merged ANZAC DF working, there are too many cultural differences. From what I've seen first hand the Kiwi's are actually (in general) more professional and proficient than their Australian counterparts in many instances (possible exception being RAAF Engineering which is pretty much worlds best practice across the board).
NZs procurement and naval engineering / project management is in general far superior, their problem being political disinterest and limited money. I suspect this is because they haven't had their engineering and support organisations gutted in the way the Australian Army and RANs were in the 90s and 2000s and political disinterest can actually be preferable to excessive political interference, i.e. the total wrecking of a reasonable system in the late 90s for political gain and then adding layer upon layer of compliance and non-decision making to address the problems created by the originally politically inspired reorganisation.
The system that successfully acquired the Leopards, FFGs, Fremantles, F/A-18, Seahawks, Blackhawks, ANZACs and Collins to name a few (with no major program failures to mention) was replaced with a very bureaucratic system that resulted in the Super Sea Sprite, FFGUP, LCM2000, MU90, MRH90, ARH Tiger, M-113 upgrade, multiple attempts at an ANZAC upgrade before something reasonable resulted (but with platform issues yet to be addressed), Armidale Class Patrol Boats, Vigilaire, etc. Basically procurement and project management became more onerous and difficult, accountability disappeared, ownership was often impossible to determine, service requirements were often ignored, industrial requirements were ignored except where pork was involved, and at the end of the day many decisions were made personally by the PM.