Why a naval gun should not begin as land artillery

Would adapting a modern self-propelled artillery turret be worthwhile for a ship seeking a larger gun?

A naval-gun design is the better starting point because adapting a crew-intensive land system adds complexity and is less attractive than improving existing 5-inch technology.

Modern self-propelled howitzers are built around land-service crews, support arrangements, and operating environments. Turning one into a naval mounting would require stripping out or redesigning many of those systems before addressing the shipboard installation itself. An existing 5-inch naval design provides a better starting point because industry already knows how to make it. Twin 5-inch guns could increase available fire without creating an entirely separate calibre, factory chain, and maritime support system. The answer makes industrial continuity and integration as important as the nominal size of the shell.