Japan did dominate the allies at the start of the pacific war. After Pearl Harbor they proceeded to invade Thailand, Singapore, Philippines, Guam, Burma, Borneo, Hong Kong and capture Wake (just in December).
In Janurary they invaded DEI, Dutch Borneo, advance in Burma, invade Rabaul, Soloman Islands.
Feb Japan invades Java, Sumatra, (Britsh surrender singapore), Japan air raid against Darwin, invade Bali, and they also found time to shell an oil refinery near Santa Barbara.
March- Brits evacuate Rangoon and Japan invade New Guinea, Andaman Islands in the Bay of Bengal.
April- Batann death march, and they take central Burma
May- Japan occupies mandalay, and on May 20 they complete capture of Burma and reach India.
Only six months after Pearl Harbor Japan is on India’s doorstep, they controll all of the DEI as far west as Wake and are a stones throw away from Australia. If that is not domination I don’t know what is. The only reason we are able to say we owned the Japanese during WWII was because we broke their code and were able to read their play book for two very important and decisive battles, Coral sea and Midway. In fact the battle of the Coral sea on May 7-8, 1942 was their first defeat in the war, and Coral sea was really more of a draw. The big turning point was Midway and without having broke the code I think we would have lost that battle.
After the battle of Midway it was all downhill for Japan, they were not able to regain the momentum and they ended up getting dominated by the allies. I think the P40 is the same way. If they allies can withstand the initial onslot of Japan the tables will turn and the allies will dominate, just like in the real war.
Reference: http://www.historyplace.com/unitedstates/pacificwar/timeline.htm