The term 'Napoleon complex' is used in reference to Napoleon Bonaparte who many believed conducted his tyrany and invasions as a form of overcompensation for his short stature.Interestingly however the term 'Napoleon complex' may well be a misnomer.If this brought positive reward, that would then be a form of positive reinforcement that could condition them to behave this way.
Other personality traits have also been linked to Napoleon syndrome for instance risk taking behavior and jealousy.
Thus it might not be that smaller males are more prone to attack first or act noisily but rather a case of 'gentle giant syndrome' where the larger individuals are more reluctant to engage in confrontation and the smaller individuals look more aggressive as a result.
There are other possible explanations for short man syndrome however.
In the case of short man syndrome it may be that in the wild smaller individuals needed to make more noise and act more aggressively in order to compete for food and mates.
Indeed studies have demonstrated that in the wild, smaller creatures often do attack first.