These are five discrete novels unlike Paul Scott's Raj Quartet, Galsworthy's Forsyte Chronicles, or Trollope's Barchester Chronicles and, as such, can certainly be read as stand-alones. The reader will surely prefer some stories more than others. The Stone Woman was the least satisfying for me.
The author is better known as a journalist, non-fiction writer, and documentary filmmaker, and the reader will not find the beautiful literary prose of a Paul Scott with his elegant phrasing and subtle changes in tone. However, I enjoyed these stories as portrayals of Islam in different locations and historical periods.