You raise some good points Reg. The NFH is really a navalised NH90, so I would like to see some bought sans the ASW / ASuW gear to use more often at sea on the MSC and on CY. Four would be enough bringing the 90s up to 12 which would give us better helo capability and cover the extra decks plus taking pressure of the current 90s. Would mean that wouldn't have to send the Sprites away on the these ships leaving them for their main missions and if needed on the OPVs..
So what your suggesting is for want of better words is a Romeo and Sierra versions of the NH-90. The "Sierra" version equiped with AQS-20A and other AMCM detection gear would be a very useful capability looking ahead.
BAMS / Stanflex / Venator like vessels are a no brainer really for the RNZN. The ability to swap out / add and re-role quiclkly through mission packages the vessel, from a benign HADR tasking through to effectively a Corvette/Sloop of War like surface combatant, then into a MCM/DSV and then back into benign EEZ OPV, with other role such as sigint/elint, environmental protection, MAOT tasks such as logistic supply of DOC staff on small island research bases. That is exactly what we need and should have had planned a decade ago rather than the former Labour Governments reheated version of the Irish Naval Service.
In many respects the ship specifications we really need is not yet built COTS - but other than the hull and superstructure everything would be COTS. The big Korean shipyards could do something with an eventual class of four. Something along these characteristics - circa 3000t, 100-105m, 40 days endurance, 10000km+ range, 22kts+ but ability to loiter under 5, Base crew of 35 plus 10 aircrew and 10 observers with a further accommodation capability 30 personnel short-stay - mission specific (Ideally further austere emergency accommodation as well should be possible for evac/refugee sits), 3D surveillance radar + sensors, surgical/Med suite, 1A ICE, Bofors Mk 110 57 mm as a std main gun, mini tyhoon, light CIWS like NARWHAL, medium heli capable flight deck and hangerage, workshop, flexdeck, 6 TCUs, hydraulic crane for mission packages / swap outs (including deployed small survey/inshore launch per SMB Adventure), decompression chamber and MCM drone et al). I would be looking at a palletised Point ADM and ASW capability swapped on/off as needed because it is essential that the vessel type can swing roles from EEZ roles through to anti-piracy, LIC, sealane escort. or directed taskings in a Chp VII maritime environment. If we include module / palletized system some things like Survey / Dive and MCM could be cross decked with the LWSV and vive versa. Though the LWSV is likely to be different vessel synergies should be there to backup, support and complement. Though I envisage 4 next generation OPVs the LWSV is will be in many ways a defacto 5th OPV.
The above would generally be my design/capability parameters for the next generation "OPV" (following the Endeavour and LWSV introduction) that may replace the first 2 IPV"s to go, then the next 2 IPVs replaced, then the Otago and then Wellington on a bi-annual basis. To replace the IPVs, which the Navy didnt really want but Clark/Goff/MFish did and the OPVs which to use a kind phrase - are underwhelming, a few years early, (they will have a useful second life with a small-medium developing nation, thus a win-win all round) and follow up that build program with the CY replacement (13000-15000 tonne LHD that I have previously outlined and advocated) and then a couple of very capable Anzacs to polish it all off.
At that stage or even a few years before, we would have a better read of the geo-strategic tea leaves post 2030 and decide whether to commit to a 3rd Anzac, or follow up with another batch of Gen II "OPVs." I would be initially inclined to keep the CY in reserve or limited use status as a cover or Sea/Aviation training role manning suplemented through VR personnel, because though the CY replacement vessel will be much better in a JATF role, the reality is that we can only afford, sustain and man realistically just one. It will be a more complex and capable ship and a cornerstone capability for a post 2025 NZDF. And it cannot be at sea permanently 24/7/365 or if it is away as part of a major TF/Ex with the next Endeavour, 2 Frigates, the LWSV and possibly a kitted up OPV in Vette mode and a Tsunami hits Samoa or the locals on Niue go troppo, then it could be quite a useful backup. I do want to make the point a small LHD vessel as the CY replacement would also benefit from the swap in / swap out modularized capability of the "OPVs" and actually when not in JATF / Sealift / HADR mode would be able to operate deployed rotary assets ala NHF-90 or MH-60R/S sailing independently in long range peacetime patrols possibly in lieu of a costly 3rd Anzac.
Cheers MrC