Nice AAR but some issues...
Wasn't Yugoslavia in the Balkan Pact until 1941?
Impossible to have attacked ANY of those countries as I'm sure Mussolini contemplated both Yugoslavia AND Greece, but they formed a pact. They would have opposed strongly and mobilized for sure, this needs fixing ASAP I think...
Not until Hungary and Romania were pulled into the Axis side did the pact start to fall apart. And both those countries acted in that way due to the thread of the USSR moving into Bessarabia and Northern Bukovina in 1940.
Wiki says the pact was resolved in 1938 but that's not true, it held out until the Axis decided they wanted this area to either become satellites or be occupied. An attack on one of its members, Yugoslavia in this case, would have at least raised HIGH threat levels in Greece, Romania, Bulgaria, Turkey, Albania and Hungary. ESPECIALLY if Italy is occupying and KEEPING the whole country.
Then, seeing the dismal performance of the Italians against the Greeks even 2 years later and that not making ANY ground against simple underarmed Greek units, I really wonder Italy is ready for such a large operation against such a large army.
It seems to me Italy should not be able to select Blitz tactics, how can it get that when no blitz was ever performed and the Germans invented it basically...
See
http://www.sosyalarastirmalar.com/cilt2/sayi6pdf/degerli_esra.pdf