Actually, just waiting for Makedonia and the southern Hellenes to fight it out will result in an economic crisis of the likes Greece faces today. The best thing you can do with Epeiros, is blitz Greece from the start to save your rapidly failing economy.
Not so, taking some of the northern Eleutheroi towns will allow you to gain some cash. Pella should be taken at the start, but in my experience the southern Greek towns are always much too well defended for a direct attack early on.