Unfortunately, people during G40 second ed revision suggested this modification.
But Larry stick to Naval Cost structure
4 points = 8 IPCs,
6 points= 12 IPCs,
8 points, 16 IPCs + 2 hits, 4 IPCs = 20 IPCs.
But I don’t believe it was so good reasons.
It doesn’t consider the impact of DD’s Anti-Sub capacity.
And adding 4 IPCs for an additional hit is more or less arbitrary.
It could have been put at 2 IPCs, making BB an 18 IPCs unit.
Or A4 D4, 1 hit worth 14 IPCs + 1 hit at 4 IPCs = 18 IPCs Battleship.
Or this hypothetical cost structure would have been balanced too:
Sub A2 D1 C6 Surprise strike
DD A2 D2 C8 ASV
CA A3 D3 C11 shore bombard
CV A0 D2 C16 2 hits, load 2 planes
BB A4 D4 C19 2 hits, shore bombard
But 19 is not a square price.
But 18 IPCs is 6 times 1 Infantry.
And 10 IPCs is a square number.