@gamerman01 if we want historical accuracy, we would have more battleships and cruisers still built in the game. Here are the splits for the US navy:
By the end of World War II the U.S. Navy was by far the largest and most powerful navy in the world with 7,601 ships, including 28 aircraft carriers, 23 battleships, 71 escort carriers, 72 cruisers, over 232 submarines, 377 destroyers, and thousands of amphibious, supply and auxiliary ships.
Translating into axis and allies, we would have roughly similar spend/turn on battleship, cruisers, subs, and destroyers, and a bit disproportionally high spending on carriers.
In terms of practical proposal, I would have cruisers cost 10 and battleships cost 17. Willing to get feedback if these numbers are attractive.