Would the Battle and Daring classes arrive earlier?

Would war with Japan bring something like the Battle or Daring class into service earlier?

Probably: the lessons could accelerate a Daring-like development, although the exact design and date remain uncertain.

Combat lessons against Japan could bring an advanced destroyer comparable to the Battle or Daring class into service earlier. The likely ship is compared with the L70 design, without claiming that the historical Daring would appear unchanged. Wartime experience would turn operational lessons into an earlier requirement. No firm completion date is given, so the timing remains a broad counterfactual.