The A321 might be an alternative to the B757, but Airbus does not currently have any alternative to the P-8, aside from a C-295 in MPA configuration. Not exactly what I would consider a peer in terms of capability.
It is also questionable whether another civilian-based jetliner with the capabilities of a B757 would really make sense for the RNZAF. We have had the discussion here before, one really needs to ask, what missions does the B757 perform well at, why, at what cost, and are there other aircraft or methods to meet those same missions at lower cost and/or to a greater degree.
Exactly, the P8 type P3 replacement will be the driver in this particular area, any B757 replacement will be a bonus and currently only if it will have synergies with the MPA fleet to bring down cost if ownership. The B757s for us are pretty unique in that other current options are either too big, not big enough or lack range or take off weight as viable replacements, another mark against their succession and survival
B757s have been pretty busy lately and I think govt have seen this, yes we could do these tasks with hercs but would we want to is another question. Cost also equates to practicallity and everyone seems to think everything RNZAF does is combat in nature and austere in location which could not be further from the truth. Yes it is a portion but definately not the majority. It would be like government swapping the ministarial BMWs for some hiluxs, would definately save money and no doubt be just as useful if not more in areas but they do have a purpose to serve.
The boeings are just the next easiest capability in line to cut with the least amount of justification as apparently there are other options that can do the job 'just as efficiently'. End of the day it would just be yet another capability gone without proper replacement in an effort towards 'savings' and just like civilianisation, downsizing, downgrading and amalgamation seems like a great idea until you do it. What's next, frigates? P3s? another base?