"Napolean complex" is already a term. The "little man syndrome" is less literate; unneccessary.

Condition whereby undersized men compensate for their smallness by physically asserting their presence.

A man, small in stature, who attempts to overcome the way he believes other people perceive him (as a diminuative character) by 1) attaching himself to authority figures, 2) trying to manipulate himself into positions of control, 3) migrating toward positions of leadership, and 4) having a fairly volatile temper.

When a small man feels the need to out do a normal size man in order to feel bigger then he is.

When a guy is short and has an attitude problem because he is bitter at society for looking down on short guys.

When a guy's short, but to compensate for his vertical challenge feels the need to be able to beat the shit out of all.