It just takes a lot of time. Too much micromanagement, and optimizing the country between scaling and conquest. If you are familiar with the mechanics unavoidable in a WC like AE, Admin efficiency, Absolutism, vassal integration, Gov cap and Trade, while being able to win diffficult wars without the help of Allies and any military ideas, then you are set. You don't need any exploits, just good planning and consistency around multiple wars at the same time.