Well they have made such mistakes beforeLol I forgot about that... Though to be honest I am not sure if such simple way around will work, I think pdox expected that 'exploit'.
I don´t see it as being overly nerfy, it makes you not able to do some irrational behaviour simpy for the purpose of westernizing, which brings me back to how technology works. Yes western should be superior but instead of penalizing players who want to be the "best" and compete with the great powers, they could make it more logical backwards, add some steps to become better and provide other means to play other than being western.
I like the change, that 80-90 % of the world was not western, but they were influenced by them. But this didn´t mean that these nations were incapable, history are riddled with such cases, albeit the cases I recall are not from this period but the gap was huger so the issue remains. Zulu and Afghanistan show greatly how an "inferior" nation were capable of fighting and winning over such nations