Nelson displacement and the N3 speed estimate

Why were Nelson and Rodney about 33,800 tons rather than the full 35,000, and how fast might N3 have been?

The unused margin promised little worthwhile improvement and supported diplomatic restraint; N3's hull form plausibly allowed about 26 to 28 knots.

Adding the remaining 1,200 tons needed a worthwhile purpose; using the full treaty allowance simply because it was available offered little advantage. Water and related design choices could contribute to protection without consuming all of the declared margin. A 33,800-ton figure also let Britain present the ships as restrained during treaty bargaining. The conservative N3 estimate is about 26 knots, while a calculation that gives more weight to the hull form reaches roughly 27.5 knots. King George V needed 110,000 shaft horsepower for 28 knots in a lighter hull considered less efficient at speed. The main reservation concerns the unconventional placement of the main battery rather than the ships' overall quality.