"Independent Catholic Jurisdictions" have been a thing in the west since the  Union of Utrecht of the Old Catholic Churches which coalesced sometime after 1870.  Other alternative communities existed then, some continue to survive to our day, others continue to emerge.  
The traditional question, which is totally ignored by this review (and, perhaps, the book) is the question of Apostolic Succession.  For example, some light is shone on the Catholic Apostolic Church of Antioch; how is this Archbishop Richard Gundrey actually related to the See of Antioch, or is it just a matter of Branding?

Are all of the emergent communities mentioned in the "Other Catholics" cobbled together in a back room hey presto, or do any of them have substantiated evidence of connection to the historic traditions?