Help for book organization choices

Maybe I am a bit off-thread, but this is the only docbook community I
am attending up to now, so I wouldn't know who to ask to.

I am planning to develop our company "Policies and Procedure Manual"
(which is the only company document depending entirely on me) using
docbook.

Logically, the hyerarchy would be:

Company Manual
|--- Department Manual
|    |--- Category
|    |    |--- Policy / Procedure
|    |    |--- Policy Procedure
|    |--- Category
|         |--- ...
|---- Department Manual
      |---...

Taken by itself, each Policy / Procedure is a stand-alone document,
with its own author and revhistory and sometimes appendixes and so on,
so it could be written as an article.

On the other hand, I would like to preserve the concept of the Manual
integrity, so, maybe, it could be written as a book, but I am afraid,
this way, to loose the single policy/procedure atomicity.

As I am still very uncertain among the pros and cons of each of the
two options, I would like to have some opinion from people who are
more experienced than me with Docbook about the way to obtain a good
compromise between the various needs.

Thanks