There is apparently also a rule that the directors must be American or European. IMF Wikipedia page shows all directors are American and European, with one Israeli and one Indian.
That is because the western align bloc share of the votes is a big majority. The US alone has 16.5% of the votes (China 6.08%) and adding all the other major US vassals (not including all the smaller European ones) already put them at ~50% of the votes.