Well, that is a lie. Each branch has membership and vetting processes for new members as well as ranks. Yes, the individual branches/terrorist cells are linked by ideology but each cell is run in a very hierarchical manner. Andy Ngo goes into this in great detail in his book which includes paperwork, manuals, and testimony of former members who have left the terrorist group.
Oh, and they most certainly organize crimes and attacks as well. Again, Andy Ngo covers that quite extensively show pictures of organizing posters, first hand testimony, and video break downs showing how they go about committing their crimes. That they are constantly committing crimes in organized cri.inal events is why they always attack people with cameras unless it is a pro-Antifa propagandist.