Arming a Merlin for air combat displaces its ASW mission

Is there a useful naval-helicopter role for weapons such as NSM or AIM-120 AMRAAM?

NSM integration may be plausible, but an AIM-120 fit is unlikely to be worthwhile because a Merlin carrying air-to-air missiles is not performing the ASW role for which the fleet needs it.

The later follow-up makes the opportunity cost explicit: AMRAAMs replace torpedoes, sonobuoys, and the helicopter's focus on submarine or mine threats. In a task group facing China, F-35Bs can provide fighter defence while the scarce Merlin force remains focused on underwater warfare. A technically possible addition can reduce force effectiveness when it pulls a platform away from its primary mission.