Valkyria Chronicles and tank guns at sea

What do Valkyria Chronicles' snow cruisers suggest about using tank guns as a ship's primary weapons?

The fictional arrangement is inefficient in real engineering terms because ships can carry much larger purpose-built guns; guidance and fuzing transfer more readily than complete weapons.

A tank gun is constrained by a vehicle of roughly tens of tons, while a destroyer can support a much longer and heavier weapon on a hull measured in thousands of tons. That difference changes barrel length, ammunition dimensions, and the performance available from the projectile. Tanks carried aboard amphibious ships can provide emergency fire before landing, but they are inefficient substitutes for purpose-built naval guns. The most useful common technology is therefore inside the shell, where guidance and fuzing systems can cross between land and sea weapons.