I think it mostly is... Seems to be organized by style, then within each style, things get more complex, again, generally speaking.From what I understand, the book is not in an east to hard format.
If you feel like you are having trouble with a later groove, it may be beneficial to start from the beginning.
If you bought the book to learn a specific groove, learn that one (obviously).
I think that if you bought the book just because, go from front to back.
If you bought it for a certain groove and need to learn it for a gig, go to that one.