Heavy cruisers had torpedo launchers in history, especially Japanese heavy cruisers. All japanese heavy cruisers had Type 93 Torpedoes in the WWII. Heavy cruisers of royal navy and kriegsmarine also has torpedoes.

Considering the balance, if a tier 11 heavy cruiser engages a battleship of tier 7 or 8, that is to say a super-dreadnought, it will be defeated easily. Adding torpedoes to thm could make the game more balance. Because in history they had torpedoes.