The Great Man theory sets up history as a progression of Great Men who shift events, so that the whole past could be seen as a political history, the interactions of a few individuals. ( I mean, that's the general notion....I don't know if anyone ever codified it, put out a manual on how to do it). However, in Mao's case ( and Hitler's and Stalin's) there's something more complex going on. Crane Brinton, in his classic Anatomy of a Revolution , noticed that after a big upheaval or revolution ( like, here, the chaos of the Warlord Era, Japanese occupation and civil war) societies tend to coalesce around and grant great powers to some military leader. Here, it would be Mao; in Russia, Stalin; in Germany, Hitler.
Like a lot of big theories, it's easy to start using Brinton's to pound squarish pegs into roundish holes. Brinton would put Washington into this series, despite the American Revolution not being that much of a revolution. But if Mao and the others had great powers to make them Great Men, you can also then make a good case that there were special societal conditions that put them there. And once there, they were pretty unchecked: they didn't so much interact with other GM as simply exercise extreme power, do whatever they wanted. In other words, you can't tell the story of China with biographies of Yuan Shih Kai, Sun Yat Sen, Chiang Kai Shek and Mao; there is a lot of cultural, economic, and societal circumstance as well

If you are looking for more sources, Mao's policies for the GLF etc. are outside my field. But I have heard Frank Dikotter interviewed about his new book on the Cultural Revolution, and it seems he's been able to finally use some Chinese archival sources which were previously unavailable. It is getting lots of good reviews. Here's also a good talk he gave on the Great Leap Forward that you might find interesting.