Eisenstein wanted a shot to be the opposite of the previous one - for a collision to occur. Overlapping Montage is where shots 'overlap' each other. It opens the action up, so that you can see it from various points. It also, by definition, has to further the action - these functions are at odds with each other. The idea of continuity editing is to push the narrative along.
Montage tends more to create atmosphere, mood, and ultimately, emotive impact .
It also pushes the narrative along, but allows for a greater exploration of both form and content. Metric montage determined the tempo of the editing , and was dictated by the duration, rather than the content, of each shot. Rhythmic montage, on the other hand, did take the shot content into account and gave it a valuable emphatic or contraputal function, as in sequences of sustained tension. History of Film.