Japan and Germany would have eventually come to blows.
Gentlemen,
I don’t think they could have won. Or held the conquered nations down for more than a brief amount of time.
Japan and Germany were simply too small to do so. Numbers and economic power matter most in a war, and to maintain the rule over conquered nations, you will need so-called soft power, i.e. a culture which appeals to the vanquished. That was also sadly (?) missing.