Carrier commonality and Japan's constrained alternatives

All three American carriers at Midway came from one class, giving the force broadly familiar handling and operating characteristics despite their different recent damage histories. The Japanese force mixed four designs, including the slower converted battleship Kaga and Hiryu's reversed island arrangement. Hiryu's island complicated flight control and put the structure on the side toward which pilots naturally turned away from trouble. Newer carriers such as Junyo and Hiyo expose the gap between launching a hull and bringing it into operational service, especially for a navy that knew war was approaching but lacked the industrial capacity to accelerate both ships. Had both been worked up in time, Japan could have brought six carriers and might have overwhelmed the American force. Even that success would probably have bought only a few more months against American industry.