The original premise of this thread is that Italy concentrates against Greece, rather than squandering resources in doomed or futile operations elsewhere, but receive no assistance from German forces.
I thought this part of the original premise of this thread was already proven wrong.
Italy simply could not leave Libya, because Libya was the bet of the Mediterranean Theatre of War, at least after the Italians realized that the dreams for capturing Suez were doomed.
Anyway, what most people fail to see is that the Italian attack to Greece was nothing more than a supposed distraction for the British. It takes something more than Wikipedia or "history" books that recreate propaganda as "source" in order to understand what happened then (I'm not talking personaly here - we all fall to that trap ocasionaly).
First, let's check the Italian geopolitial thought of the time: number one target for Italy was Yugoslavia, because under the Italian geopolitical thought, Italy should control the Yugoslavian shores of the Adriatic (And Albania and Corfu)= "altra sponda" (oposite shore), because this was her "Lebensraum", and would give her the necesary strategic depth, and all this was described by the term "equilibro adriatico", under the theoretical thought of Loisseau and Giomberti. Of course, in the late 1930's there was also the fascist "wet dream" of turning Greece into a client-state, but that was far lower in the agenda. Hence, there was no geostrategic reason why Italy should attack Greece (even for Corfu) before she had cleared the theatre with Yugoslavia. And of course there was no reason at all to do so while facing the British in Northern Africa. So, what happened?
The first act of the war against Greece was actualy the sinking of the Greek light-cruiser "Helle" on 15th August 1940 in the harbour of Tenos by an Italian submarine. Why did this happened? Musolini had ordered the invasion of Egypt on August 8th -one week earlier. With that torpido, Musolini hoped for an escalation with Greek responsibility. That way the British would be distracted and the italian troops would have the advandage of surprise in Egypt.
After that, why did the Italians started the war on October, i.e. the start of winter, with the front in one of the worst terrains in an area with minimum infrastructures, while they had not the necesary units, plans, and material deployed in Albania? Was the Italian Regime so stupid, as the propaganda tries to prove? What was happening then in Northern Africa? Graziani had stoped before Mersa Matruh and Musolini failed to persuade him to renew his offensive, which he planned for December. The only way for this to happen was that the British should be distracted, and use some of their ships and airforce elsewhere, and even redeploy some of their ground forces. What the Italians thought was Greece, because there was the paradigm of WWI, and because Greece was supposed to be too valuable for Britain. Should the Greek government ask for help, the British could not deny it. Note, that when this help was requested in Spring '41, the British, even though they were facing their first defeats under Rommel, deployed about 50,000 men in Greece.
Hence, it is silly to accept that the Italian regime was foolish and misleaded when it decided to launch the attack on Greece. That served as an excuse to put the blame solely on the fascist government, while this decision was dictated by mere strategy, and actually had the support of also the king and Bandoglio. The attack on Greece was a part of the operations in N. Africa. Otherwise, the Italians would have chosen another theatre and another plan against Greece, and not the actual one. Because, through Albania, no matter how many troops they would engage, at best they would achieve a very-very slow advance at a very-very high cost.
Geography is a bitch and geopolitics her puppies...