Japanese carrier production was far less than needed to ever dream of keeping pace with the Americans. The best, most modern Japanese carriers at Pearl Harbor were the Shokaku and Zuikaku; these were improved versions of the Hiryu and Soryu. I can only identify one "purpose built" carrier built by the Japanese after Pearl Harbor; the excellent Taiho (sunk at the Phillipine Sea), a further improvement on the Shokaku design. Beyond the Taiho, the Japanese only had conversions in the shipyard pipeline, and these were poor ones at that. There were several liner conversions that might have roughly compared to the "Independence" class CL conversion carriers, but not in near the number as the "Independence" class itself. The "Independence" class alone quickly put much more combat aircraft at sea and into the fight than all of the Japanese conversions and new construction combined (post Pearl Harbor). Plus, just about every Japanese conversion carrier was too slow to run with the "fleet carriers"; given their light cruiser petigree, the "Independence" class were right at home along side the Essex class fleet carriers. The biggest embarrassment for the Japanese in carrier production after Midway was their conversion of the Yamato class battleship Shinano into an exceptionally large but slow carrier (think "target") with an air group that was 2/3rds that of an "Essex" class fleet carrier. So really, the only "improved" carrier completed by Japan after Midway was the Taiho; and this could only be said to have replaced either the Hiryu or the Soryu, which were lost at Midway.
Had the four Japanese carriers lost at Midway been available at Guadalcanal, the Cactus Air Force would have been overwhelmed. Period. The American offensive in the Solomons, starting with Guadalcanal/Tulagi would not have been even attempted.