How Infante Juan might have fared in Royal Navy service

What might Infante Juan have done during World War II if he had remained in the Royal Navy without giving up Spanish nationality?

He would probably have made a capable junior destroyer officer, assuming his early service continued on its existing course.

Infante Juan is judged likely to have become a capable junior Royal Navy officer if allowed to continue serving while retaining Spanish nationality. His apparent attachment to destroyers makes destroyer service the suggested wartime assignment.