My Masters thesis was planned out in a top-down fashion, in point form . Each point became a paragraph or two in the draft version. The new one has a looser structure, with far less points, primarily because I didn't actually know what happened. Points have tended to become essays, from several paragraphs to several pages long. These have then been strung together to form the chapters. The result is "lumpy". The 1944 chapter consisted of eight of these, two of which had already been written. Another has been moved in from another chapter. On the other hand, two of those written on the weekend have been moved out to other chapters because they no longer seem to fit properly. Two essays remain to be written. The whole, however, seems to be coming together in a reasonably coherent but quite unexpected form. The essays form a completely different picture to what was originally intended.
Also, it would probably be more practical to write more and spend less time calculating how much remains to be written.