Why different empires are placed together

The Ottomans, the Safavids, and the Mughals are placed together, because of their location. The three empires were located geographically near each other, so putting them together can show the various interactions that the three empires have with each other, which would be ineffective if they were placed into three separate chapters. This is a shift in the text organization, because usually different empires are given their own chapters, or at least one of the three or four main sections in a chapter. For the future, this indicates that chapters will try to cramp more information together, because as we enter the modern world, it will get increasingly complex and there will be much more detail to cover in each chapter.