The container logics still not understood at fullest

In the discussion of childcontainer when to use it, an application of this can be seen in the demo arrrangement  : a pale rider
What I still find a difficult point is the logic of the container structure.
For the demo : a pale rider I can't reason out for all containers why there is a certain container in the structure screen.
There is now a new overview screen which is a DAW screen and is good to use.