[g_sch]

The key here is distributed coordination. In the last few decades, the most effective social movements are those that did not rely on a single organization (hierarchical or not) but instead allowed multiple organizations and actors to work together separately and embraced a diversity of tactics.

In the 50s, John Boyd did a lot of really interesting work on the idea of "mission command" and the OODA (observe, orient, decide, act) loop. Although he did his work for the US military, I think his ideas are broadly applicable to social movements as well, as they describe how "swarms" of autonomous actors can easily overwhelm hierarchical organizations due to their ability to make decisions faster.