Yamato, Montana, Lion, and the super-battleship label

What other navies planned ships to match Yamato or Montana, and what makes a super battleship?

Britain's Lion studies were its next generation of battleships, but 'super battleship' has no agreed definition here; displacement and gun size alone do not establish speed, fleet role, or equivalence to another navy's design.

The label 'super battleship' has no agreed technical definition here. Lion, Yamato and Montana are treated as successive national battleship designs shaped by different requirements. Their laying-down dates do not establish equal combat capability: Yamato's 1937 start, Musashi's 1938 start and Lion's 1939 start lead to disagreement over which American class provides the closest comparison. Lion studies also changed over time, so a proposal for heavier armor or armament needs its design date. Clarke adds an operational test: a fast battleship must maintain contact with its cruiser line, while a battlecruiser must move faster than that line. By this criterion, Yamato's 27 knots and 18-inch guns make her large and heavily armed without making her a fast battleship.