Robert Guiscard and his younger brother RogerII already tried exactly that. And they had to kick Saracen's out. Everyone from Mussolini to the EU has tried to sort the mafia out. No go.
War, mass eviction, probably genocide as well because after you kick the Greeks out everyone around them hates them. No where to go. We maybe could nick some ones land in the middle east and start a small Christian state there. And what is wrong with Sardinia? Beach, sand, good food. No drama.
I think you need to shut down and re-tool your idea. The above is a stinker.