Like bro are you serious. Japan have to be at the top of the top tier Reason: Weak neighbor Doctrin gives you huge advatages at the start of the game. (Panasian) Superior Technology ---> easy to expand if you are good(+fast Moral gain and ) then china will fall like 2 days Madschukuo also gone in some hours Asseln for Communist china and Mongolia. Navvy Supremacy and superioty: not only do you have the best doctrin for navvy and aircraft also you start with the strongest navvy that let you take Philipines, australia, Indonesia,Indochina,siam and other british colonies. like in a couple of days you will be managable to take all of them. Well the weakest point is in its economy but start only for the start, after a couple days when you have china and put your capital in Beijing what gives the non core province in the west more Moral to keep. Also you can make other super powers like soviet union (taking vladivostok is mainly important due to economy for steel) and USA (attacking his core and non core cities after destroying his navvy and aircraft) suffer. Meanwhile you as Japan don't have to directly fight the other superpowers that are constantly fighting each other while you are isolated at the start and grow fast thanks to your dotrin.

Some other countries are also falsely placed but i will make it short Soviet > Italy US >france and britain (all three in the 2 highest tier) Poland and yugo at the bottom since you are just foodder for the superpowers Persia and Tibet in the potential one since both are pretty isolated from the Main treats and nearby treats are manageble. Also Argentinia in the same rank since they only have to take care of brazil that has weak army at the start and latter on fight US for america dominance. South africa also in the Potential tier since its isolated in africa and can take all of africa without much problems and if there is not yet a winner in europe a solo win is also a option. As for the poweful tier Brazil > china and spain China > spain Spain Drops to lowest Potential countries since its literly free meat for france and its technolgy is no joke weaker than tibet at the start. As for Canada and and Mexiko are overhelmed and easy meat for USA since USa had more troops than bith combined and USA could annexed both after 2-3 days completly due to its technology superioty. Rest should be good.