We're all living in the past!
Its:
UWW - Under Water Warfare
AWW - Above Water Warfare
AAW - Anti Air Warfare
Just to be pedantic.
As for the fit-for-role option... I cant see it working...
Looking at the size of kit, AQS-971 for example, it would take days if not weeks to re-role a jet for another task. There are so many boxes/cables/screens etc etc to plug in for each bit of kit. Indeed I know of wetties that would argue that the acoustics fit could help in AWW scenarios by proving extra SA using the screen symbology.
Looking at the MR2 as a prime example, and had it been in service today it would still arguably be the best MPA in the world. It's difficult to argue against having such an airframe with a basic fit of radar/acoustics/comms/esm and having role fit kit of EOS/DASS/Spec Comms. It's a system that wasn't pretty due to the aircrafts vintage, but worked remarkably well.