ASW / ASuW is going the way of CAS where anything that can carry ordinance that suits will be able to drop it on the target as long as it has target data needed to effect the strike. The FASC RFI stipulates more than just chasing subs and sinking skimmers (surface ships).
as an example, there is serious discussion about JSF being an enabler for ASW, ASuW - it won't necessarily prosecute the closing of the loop to kill the object of desire, but it can contribute to the overall contact and combat bubble.
in a whole number of areas the P8 has a superior sensor and ISR suite that some airforces have in dedicated AEW platforms, in fact I've seen friendly arguments break out between the P8 transitioners and E7 operators. friendly and competitive banter aside, it bears cautious respect as where there is smoke.....
now I'm not suggesting that NZ get back into fixed wing combat (although personally I'd love to see it just as much as I woody up on a RAN FW FAA
),but the issue is around the rapid developments and potential around all these new generation capabilities where the platforms are not just airborne niche weapons systems, but are also flying bearers (as in comms bearer) and where they all contribute to a flying combat array.
its not Skynet, but the potential is advancing in leaps and bounds.
you buy as much future proofing as you can because your force should be in a constant state of development - hence the recent decisions by modern militaries to walk away from the one trick pony model and demonstrate a clear aversion to it
from a 5I's perspective, an ability to talk to each other way beyond each countries JOC at an ISR, weapons delivery, eared up level is pretty significant. everything on Link16 and Link22 be it air, land, sea and space bearers can talk and co-operate, the fact that the distribution can occur across all fighting dimensions and that co-operative combat is proven and tested makes it almost an imperative for any smaller force to plan that structure into any future force developments - and the planning is no longer service centric - on acquisition and capability assessments all the services get involved in looking at a "nominal" single service selection. to all intents, every acquisition becomes a purple analysis
am not trying to tell anyone how to suck eggs, but these issues are now front and centre with all the modern and remodeled militaries
looking at any platform via a single centric lens is not the best way to conduct an assessment