What if Hitler had basically refused to help the Italians out when they ran into trouble in the Balkans and North Africa and decided to divert all the resources used in these campaigns to the Eastern Front?
The Greeks could probably not oust the Italians out of Albania in 1941 without British help. The Italian forces in Albania were simply too big at that point and the latest Greek offensives were successfull, however had a heavy death toll on the Greek side too.
Really?
The Greeks successfully pushed the Italian Army back into Northern Albania and occupied half of the country.
That was before the massive build-up of troops MUC refers to. By the time the axis offensive defeated them the Greeks were hanging in the ropes anyway. The war had strained their economy to the point of collapse.
Prior to the German intervention the Italians launched a counter-attack on the Greeks on March 9, 1941, they called it off after two weeks having failed to gain any ground. And the British were by that time providing assistance.
Without German intervention there was a very good chance that the Greeks would have gained all of Albania.