No, I'm not saying that. The war was indecisive up to the point the Germans attacked, with a heavy slant in the Italians' favour becoming heavier as time passed, but Italy didn't manage to end Greece on their own before Hitler decided he would show his vassal ally how you get it done. I'm saying that "Greece won the war against Italy" or "Greece would have won, given time" is ridiculous - and Britain intervening more was a nice tale, but while there were fears, the British army was already fighting almost everywhere, and what they could give they had given. There would be no wonderful charge of British troops to save a Greek army that, while having bloodied Italy way beyond what it would have been reasonable, was going down the drain.