Completion percentages hid the Lexingtons' treaty advantage

Were the 1920 South Dakota battleships really further advanced than the Lexington battlecruisers when the Washington Treaty stopped construction?

Some South Dakotas had a higher accounting percentage, but the Lexington programme had more useful assembly progress and, crucially, could be modified to fit treaty limits while the heavily armoured South Dakotas could not.

South Dakota completion figures included large procured items such as guns and turrets that were not necessarily installed in the hulls. Material sourced for a programme is different from a class physically advanced toward completion. More importantly, the South Dakotas were designed around a fully loaded displacement near 48,000 tons and carried armour that was difficult to remove. Lexingtons were closer to a tonnage that could be adjusted or plausibly reported within the treaty framework, making conversion and retention far easier even when some accounting figures appeared lower.