[Gian]

In the early 1500s, Machiavelli was tasked with raising a city militia in Florence and later on reported his experience in both his books The Prince and The Art of War. He strongly disliked the use of mercenaries, which he considered a door left open to foreign powers, and advocated an all-Italian army modeled after the Roman legions.
Anyway he had to admit that his dream was almost impossible to fulfill since noblemen (the officers) had a poor leadership and peasants (the men) did not like the discipline.

I believe that Machiavelli hit the nail on the head but the problem has been left unresolved until the present day: this is a possible explanation as to why Italy failed to produce more than a handful of capable officers above the rank of Captain. (Of course, let me say, the courage of the average Italian soldier is out of question).
IMO careerism and "mafia networking" must have been more important than merit in the higher echelons at some time in history, otherwise I would not explain the major defeats suffered by Italian Forces between 1860-1918 and in WWII, which could have been avoided by leaders with genuine strategy skills.

[Lupo Solitario]

Largely I think no. Machiavelli failed in his idea to reform roman legions but certainly he couldn't compare the roman republic italics with his renaissance people. Soldiers as swiss pikemen or spanish light infantrymen were the result of an historical process which couldn't be recreated by simple will. Again probably Machiavelli was not the man to apply them. Giovanni delle Bande Nere obtained very better results with the same men.
Again, less of a century after, Mauritius of Nassau created the modern regimental system just studiyng the ancient legion system.

It must be noted that during the XVI century italian wars, many of the best generals as Bartolomeo d'Alfano, the Colonna brothers, Ferdinando d'Avalos and Giovanni delle Bande Nere were italians leading italian soldiers.
In the period between 1550 and 1750, italian officers and troops positively fought on all European battlefields and names as Emanuele Filiberto di Savoia and Raimondo Montecuccoli are still full respected.
Paradoxally, a more real fall of italian quality in combat was between 1750 and 1800.

So what? All those people didn't fight for something identifiable with "Italy" in some way. What really lacked and largely STILL LACKS is a structure which can form and use them in a correct way. The real trouble of italian military, in my opinion, is the italian "concept of state" and not the people skills...