Romeo vs Sierra
The Sierra tailwheel (similar to Blackhawk) is problematic for operations from frigate size vessels - it will limit the ship motion envelope that can be accepted. The USN operates these aircraft from larger (i.e. more stable) ships.
Modular ASW systems sound good in theory, but they are always a compromise, and they never just "slip in and slip out" - plugs break, mounting feet get burred etc. Ask anyone who worked with the RAN S-70B-2s about pulling ASW gear in and out - not always a simple task.
What is needed is an aircraft which can do both ASW and utility.....wouldn't that be a great thing.......