I'm no expert on Arab history either, but I don't see why it wouldn't work. When the French and British carved up the Arab region of the Ottoman Empire after the Great War, what did they use to base their regions, and the borders of the modern states? I mean, they are all Arabs (except the Kurds) so why couldn't they live in a single state? Since the Arabs of Iraq seem to put more basis on religion than nationality, would all the Sunni not be able to live in a single state? I don't know why it didn't work, maybe ideological differences in Egypt and Syria.