The speed gap lets the Japanese force choose whether to close, so the simplified experiment makes the Americans look tactically constrained. A real US fleet would include fast cruisers and destroyers in large numbers. Those screening forces mean seven battleships would not normally meet five opponents as an isolated battle line. The scenario is a controlled comparison of design tradeoffs rather than a prediction of a historical fleet action.
Notable Point · 1:12:30-1:13:00
Why the bare battle-line test is artificial
The isolated battleship encounter is a controlled design comparison, not a forecast of how complete American and Japanese fleets would fight.