Production of the 1,094 A5Ms was spread across Mitsubishi, Watanabe, and naval arsenals, so no single factory delivered the whole fighter force. The roughly eleven thousand A6Ms built during the war were never all available at once, especially at its beginning. A5Ms remained on carriers, while older A4Ns and Army Ki-10s also covered China, secondary theatres, and air-patrol duties. Several carriers still used A5Ms in 1942 despite the Zero's prominence. Actual force structure followed the airframes on hand rather than an ideal table of organization.
Notable Point · 17:43-21:18
Why older fighters remained essential in secondary theatres
Production totals never meant every squadron had the newest fighter, leaving A5Ms and older biplanes to cover carriers and rear-area patrols.