The Italians have the most room to grow and would benefit from simple changes like not having to fight everywhere at once and instead focusing on the Mediterranean (a Mussolini problem more than that of the military per se). So no Russia, no Greece, no sending an air expeditionary force to France in 1940 for the BoB. That alone allows for a much easier time for Italian compared to OTL and helps the Axis overall by not being overstretched at critical points. Italian forces have limited utility at best in Russia, had no business being in Greece, nor any point in fighting in the BoB. All of those saved forces not deployed could instead be deployed where useful in North Africa or not raised at all, which allows more supplies to be sent to North Africa. Its really hard to do away with the crony officer corps in a dictatorship, because part of the reason the dictator is able to keep power is by keeping the reigns of military power in the hands of supporters; ergo the officer corps is selected for loyalty before competence. The over-expansion of the Italian army could have been avoided without all the commitments everywhere, which could have helped make sure there was enough quality manpower and equipment to fight in the one critical theater that remains if this scenario happens. Without Greece a substantially larger shipping element is saved for North Africa, same with the naval forces, and same with the army. Perhaps the Italians have enough left on hand then to actually invade Malta in 1941?