Hijacking thread here but anyways I thought the doctrines would be
Motorized Infantry, which has access to various types of light tanks and troop transports, late game anti tank would be the Semovente 90/53
Bersaglieri, Basically some of the most elite infantry in the world, would also have access to large amounts of motorcycles. Their antitank would be somewhat lackluster as a drawback to the incredible infantry, something like light at guns and anti tank rifles.
Lastly there would be the Blackshirts/CCNN, they would be similar to the Wehrmacht terror doctrine, being the Italian equivalent of the SS. Would probably be supported by Carro Armato P 40s which were pretty much the only heavy Italian tank.
The main Italian army would consist of the normal units, infantry and such no heavy tanks, at most late game medium tanks. However Italy would have access to early game tankettes such as the L3/35 and a nice anti infantry light tank in the form of the CV-33 which could be upgraded to carry a flamethrower similar to the flammenwerfer half track for the Wehrmacht.