Che Guevara has never been President or Prime Minister, anyway.
Mussolini could not be portraited on Italian coins, because this "honour" was reserved to the king. Let's not forget, Vittorio Emanuele III was an important numismatist and coin collector (and more interested in numsimatics than in his states' affairs) and he would have never allowed Mussolini to change this law. After the birth of Italian Social Republic, dies were transeferred from Rome to Aosta, so that there were no change in coinage.
Hitler, simply, was not interested in such a thing, that he would have probably considered as monarchist... Anyway, there were some projects to coin "Hitler coin" but Germany was at the end of its most obscure period