Britain historically paused some capital-ship work because war with Germany made escorts the immediate priority. A Pacific-first conflict confronts a major surface and carrier navy, so capital ships and aircraft carriers would retain priority. King George V-class construction would accelerate, Lion-class ships would proceed, and older Queen Elizabeth-class units would remain useful until replacements arrived. Later estimates place a heavily mobilized Royal Navy at roughly two dozen capital ships by 1942, though that number is explicitly counterfactual. The identity of the first enemy changes the entire industrial allocation, not merely the deployment map.
Notable Point · 2:14:23-2:15:33
A Far Eastern war keeps carriers and capital ships building
Fighting Japan first would reverse Britain's historical decision to prioritize escorts for the European submarine threat.