A 1940 fleet swap gives Britain powerful ships for the wrong war

What if Britain and the United States swapped all battleships, cruisers, and carriers on 1 January 1940?

Britain gains impressive American hulls but loses the armored, radar-equipped, globally distributed fleet mix suited to the war it is already fighting.

The counterfactual uses 1 January 1940 and includes ships already under construction, which makes the cutoff as important as the ships in service. Britain would receive the Lexingtons, Yorktowns, Ranger, and Wasp, along with North Carolina- and South Dakota-class battleships, but no Essex- or Iowa-class ships yet laid down. Hood, Renown, and Repulse remain British because the question does not include battlecruisers. Britain loses its armoured-carrier construction programme and faces a shortage of light cruisers. Larger American carrier air groups offer benefits, but their hulls and radar arrangements would need adaptation for a war already being fought in confined waters. Crew nationality is assumed to remain unchanged, while transfer of the aircraft is left uncertain.