Hi Matt,
I never bought Andy Crowe's product so I cannot comment on that
Let's use an example to help you understand:
Our project is to write a new book, let's say a compilation of short stories. We break down the scope by chapters and list them on the WBS
Book
- Find a story writer
- writes a story
- editing
Here we define each work package by chapters, and we can't break them down any further. Although it is broken down into a granular level, we can't tell our team member to "just finish chapter 2". That's when you need to go further and define the activities in order to fulfill the work packages.
Hope this helps,
Joe