-"Adventurer's Guide of Golarion"
Limits this book's appeal to people.
-"Adventure Group Guide"
-"Adventure Guild Guide"
Still sounds generic, but includes the group aspect.
The title as it is now is so broad, that it appeals to a maximum number of people, which is understandable from a marketing pov, but sounds wrong somehow in context to the content.
Of course a character doesn't has to become a member of a group to pick up a feat, spell or item, but it has been developed by that group.
This should somehow be reflected in the title imo.
Otherwise the content could be anything with this title.
Personally, I think Ultimate Organizations would be a fitting title.
Might be a little late to change it at this point, though. In general, I'm perfectly fine with this book and look forward to it. Since its primary focus seems to be on character options instead of fluff, the RPG line seems like the best place for it. Should be interesting.