@CleonI know the book is not about 442 box formation, but I have to say that this book (+old brazil five 10's, old box article) has really opened my eyes on how to defend with narrow formations. In the old article you had cm/su infront of roaming regista, because you needed some one to keep his place in the middle. In the new formation you ask AP/su to keep his position. What I realize is that you could also do other way around too and let for example a carrilero to defend the flank and have dlp to sit on position.
I know this doesn't sound a lot, but really helped to create "invincibles" with Vieira in segundo volante role + Henry role as a raumdeuter. I'm now playing with asymmetric 442, because of your book.