Of course they are OP - the same same sense that the USA is OP, because it is based on how the countries were prior to WW2.
I mean, Japan is OP as well compared to many nations, in fact every major nation is OP relative to the non-major nations as far as I can see. It just is how it is.
But there are ways to still win even without being "OP". The USA is slow to build up, and could be defeated by not allowing them to build up their military power, perhaps through a major naval invasion by Japan. Russia can be defeated through a combined Japan/German push, or simply by a German push that is fast enough to take over their capitol and enough of their land that they no longer have a major manpower advantage - something entirely within the realm of possibility.
I mean, Japan is OP as well compared to many nations, in fact every major nation is OP relative to the non-major nations as far as I can see. It just is how it is.
But there are ways to still win even without being "OP". The USA is slow to build up, and could be defeated by not allowing them to build up their military power, perhaps through a major naval invasion by Japan. Russia can be defeated through a combined Japan/German push, or simply by a German push that is fast enough to take over their capitol and enough of their land that they no longer have a major manpower advantage - something entirely within the realm of possibility.
- 1