The best would be IMO if the scenario started just after the Pearl Harbour attack. This is because even if PH was possible due to the game mechanics, it'd be quite certain the AI wouldn't choose to do that (unless you hardcoded it to - in which case a human US player could exploit that heavily).
One problem I don't think was mentioned yet is that the game does not adequately model the surprise effect of the japanese attack.
One problem I don't think was mentioned yet is that the game does not adequately model the surprise effect of the japanese attack.