I not sure about your numbers from looking at Navweps weights.
For some reason SpringSharp was estimating that ten Mark 6-class + twenty 5"/38 DPs weighed 4,229 tons while twelve Mark 6 + sixteen 5"/38 DPs was 5,148 tons.
In reality, the US was looking at only 3,218 tons for twelve Mark 6 + sixteen 5"/38 DPs.
Twelve Mark 6 = 4 x 3 guns (from navweps North Carolina (3) and South Dakota (3) Weight 1,403 - 1,437 tons (1,426 - 1,460 mt)) = 5704t
Sixteen 5"/38 DPs = 8 x twin (Mark 28 Mod 0: 156,295 lbs. (70,894 kg)) = 567.1t
Total = 6271t ? its even more than springsharp says ? rather than 3,218t ?
Not sure what I'm getting wrong ? do you have more details, thanks JSB
(As to springsharping weights its hard as I don't know accurately thickness's for protection, but I get (16'/5'),
Guns 1,375 / 45
mounts 2,644 / 139
Ar 2,110 /110
total 6,129 /294 = 6423t total close,ish and I think I may have added to much protection to the 16' guns and the 5/38 are a bit to light. )