Had the Washington Treaty not been signed, Japan would have had perhaps six more capital ships and the USN ten. The pre war carriers on both sides might have been a few thousand tons larger and there might have been two or three more each.
Japan was going to be destroyed in about the same time as they did in real life no matter what unless the US did nothing- and there was no realistic chance of that.
That is the same kind of over confidence that made some think PH was not vulnerable. Inflexible.