There is so much noise in the space of Software Architecture. And I think is something natural: building software is not architecture, nor engineering, nor mathematics... still it is all that at the same time. It also has strong social, linguistic and design components. Maybe it is just too new a discipline to define it clearly.
Personally I find these resources more convincing than the booklet or the references mentioned inside it:
For the technical/organizational (Dev teams) part
Architecture without Architects: https://www.youtube.com/watch?v=qVyt3qQ_7TA
Clean Architecture: https://www.youtube.com/watch?v=Nsjsiz2A9mg
For the Enterprise Architect part: