It should be remembered that the Canterbury (Can'terbury?) was originally ordered as the "multi-role vessel" part of the Project Protector fleet. It therefore had many objectives - resupply of our outlying islands (Raoul, Campbell etc) plus the Antarctic operations, plus supplementing the OPV's for offshore patrol, no doubt new sailor training, chopper crew training, oh and yes deploying the Army. Whenever you want a single unit to cover many bases, it tends to not cover any of them well. I suspect that Tenix, the frontrunner with the OPV and IPV designs, always had the inside track for the MRV, no matter what it offered.
The original Maritime Review also recommended a 57 - 75mm gun for the OPV's and MRV - instead they get a 25mm naval Bushmaster. So much for indirect fire support.
I would suggest that the 250 personnel capacity is perfectly ample for NZ, we would struggle to achieve that level of deployment!
The Project Protector budget was NZ$500m - at a time when that was US$200m. The MRV aka Canterbury was slated for half of that. However, with high domestic interest rates pushing up the NZ$ value cf the US$, Canterbury ended up costing NZ$177m according to the recent reports, so we saved money over the budget - but dont get the value in terms of utility. How was the NZ$500m cap calculated? Good question - probably plucked from thin air, or because the new army-centric government saw that the previous one had allocated that for the army, and switched the funds. So we spend NZ$1billion on army vehicles that we will use occasionally (and no doubt even less operationally) versus less than NZ$500m on ships we will use regularly. Great prioritisation! Go figure that!
BTW the survey ship HMNZS Resolution (formerly USNS Tenacious) can carry a towed array from its former life as Soviet sub monitoring ship, and I believe we have used one for various survey work.
Anyone for the Danish design to supplement the ANZACs and Canterbury? We could dress that up for frigate style ops or down for supply operations, and with 2 chopper hangers and vacant deck space it gives more options - a concept I admit I abused above, but can work if you dont overload it with expectations!