@ Lancaster Bomber: The DefPros out there would be best to answer that question (as to whether it is viable etc).
But like anything I suspect the answer would depend on Govt-Govt discussions to make it happen (and to get the ball rolling - CN-CN (Chief of Navy) discussions, depending on the strengths of their personal professional relationships etc). I suspect it isn't on the CN's radar anywhere eg RNZN CN may be concerned with filling exisiting surface positions and ensuring talented staff don't leave. Similarly RAN CN may not want it to be felt that they have to call upon the kiwis to help them out etc. Eg patch protections on both sides.
Which is a bit of a shame when you think about the bigger picture, which is ensuring both country's expensive assets and capabilities are fully functioning at max capacity, to justify the huge defence investments etc. For if it were wartime, no one will mind whether your colleague is from another country, as long as they could do the job etc.
Again the DefPros would know better than I but I suspect there would be a few high achievers in the RNZN that would like to progress their careers and try something that is different i.e. subs.
Which neatly falls into Todjaeger's post about Rifleman James McKie. According to
this link he joined the British Army in 2006 as a career move (and note his comments at the end "As far as the military experience goes, this is the ultimate for a career soldier"). I don't know the figures but I do know that some NZDF staff do resign and join other forces for career development reasons. It's easier to join the ADF or British Armed Forces due to compatible rank and structure etc. Some people want that sense of adventure and one can only go so far in NZ etc.
Hey another thing I mentioned in my previous post (and I'm sure you said it too a while ago ... and others previously also) is that although the ideal is for OZ and NZ to have 5:1 ratio, which was more or less the case until the aftermath of the ANZUS bust up for us eg RAAF 5 strike sqns v RNZAF 1 strike sqn or RAN approx 14 surface combatants (+ 6 subs) v RNZN approx 3-4 surface combatants etc or 24 Hercs v 5 Hercs (although the RAAF picture has changed with the C130J/C17 combo now etc).
I mentioned that this is no longer the norm here in NZ nowadays (again more or less since the mid-80's) eg there is no way NZ would have say, 1.2 subs v OZ 6 subs, or NZ 20 JSF's v OZ 100 JSF's etc, it ain't going to happen because the NZ Govt (either major party) will do what it feels it ought to do, not what another country wants it to do (seeing that NZ isn't in ANZUS and thus doesn't have the US "pressure" behind the scenes to keep up etc).
But the problem here is that when NZ does (did) have a capability, let's say the air combat sqn of A-4's, the problem is maintaining this investment not only in aircraft, operational and training costs, but periodic upgrades (periodically these can be huge costs in the order of hundreds of millions of dollars etc). Which means say the A-4's don't get these upgrades in a timely manner and more or less become useless for coalition type operations (eg they may not have the latest counter measures, data links, weapons thus doctrines) so they are seen more as a liability for coalition partners eg think GW (when the A4's were considered but not offered) or maybe even East Timor as per Mr C's & GF's discussions in the RNZAF thread a couple of months ago. Which isn't necessarily an issue if the NZ Govt is happy to allow the bigger players undetake these roles and keep the A4's for worse case scenario all out war in this region etc. But the problem we then have is, if they aren't deployed they aren't used and the Treasury (and the peaceniks) start worrying about investments that can be considered white elephants.
Perhaps then, in this new era of proposed ANZAC cooperation, NZ and OZ should rethink this 5:1 model. For example, if OZ is to buy 24 Super Hornets to replace the F111's for long range strike, hypothetically then (and as there is no way NZ itself will buy a full sqn of 14 or so SH's, maybe NZ should only be buying approx 5 SH's (5:1 approx). Whilst only 3 or so may be operational at any one time, is this really an issue in peacetime? In "wartime" the 3-5 NZ SH's would reinforce the OZ ones, despite the numbers being low at least the NZ ones are full kitted out with the same level of expensive counter measures and so on. At least logistical support would be 100% compatible etc. For me personally, the ideal would be an RNZAF with "long" range strike capabilites to operate with the P3's to deter/counter any hostile martime force in our region or SEA, long range interdiction, some air-air for defensive reasons (and maybe stuff the CAS role for the Army)?
Ok this theory does fall down in places eg if ADF ever acquires 100 JSF's, I still couldn't see NZ acquiring 20 because of the overall costs (and operational/upgrade costs), but maybe the answer is, NZ doesn't not entirley emulate the OZ situation in all cases, eg maybe we buy I dunno, 8-10 SH's and forget the F35 for the timebeing (at least not for another 10 years when prices drop etc)? After all what's it to be, NZ with a small but properly functioning ACF that can seamlessly slot into an ADF OrBat or a second rate NZ ACF eg A4's (or none at all as at present)?