I found this article while searching for info on another director actually. I thought it was interesting. The writer analyzes the conclusions of the Dollars and Godfather trilogies; how Leone and Coppola use what he terms to be "operatic montage". He defines operatic montage as a synthesis of montage and mise en scene. In the course of his discussion he talks a bit about film and editing theory, Eisenstein vs. Bazin, antirealist vs. realist approaches to film. I thought it also underscores how Leone's background of working with Hollywood and Neorealist directors was important in formulating his own style and approaches. Here's link if you like to read:
http://pov.imv.au.dk/Issue_06/section_1/artc8A.html 
