Each CBZ covers 1 arc. The problem with this series is that there are multiple side story arcs set in between main arcs. These arcs don't really have any connection till like the end. So this is just me trying to make a more suitable way to read the series. There really is no point trying to read the side arcs in between the main set of arcs when they have no connection to the current arc in the first place. So they have been seperated.