In my opinion, there is a problem with the word 'greatest'. It presupposes personal priorities. If one considers Scipio, it might be said that were it not for him, the Roman Empire and the present Western World might never have come about. Caesar, Augustus, Justinian, etc., might never have existed as great men. Scipio's contribitution was mainly in the field of war; Caesar in both war and politics.
To me, it seems that time, place and manners (the evolution of weapons and tactics in war; the evolution of concepts and ideals in politics, etc.) must be considered. Are Alexander, Caesar and Scipio interchangeable when the aforesaid are considered? Would any of those men have had their successes and failures in the China of their times or a thousand years earlier? I doubt if any would claim that Brutus or Pompey were Caesar's equals or Hannibal, Scipio's. Yet, these were 'great' men.
Since we cannot get in between Caesar's ears, it is possible that he had the good of the state in mind (in his terms), rather than personal aggrandizement.
My ignorance of Italian is monumental, but I believe the word 'fascisti'(?) means 'doer'. I would appreciate it very much if someone would give me a definition of 'fascism'.