If you have 10 documents then little need to number but let's say in a complex operation there are 100 documents in a manual. How do you order them in order to find the document you require?
Still waiting for answers: why do you number them? Why does it make them 'easier to manage'?
Unfair really, you aren't answering any of my questions, but instead are asking one.
I doubt I'd number 100 either. My rough answer (without knowing any more detail, which is essential to good design of document systems) is I would
group them in a way that made sense and enabled the users to find what they wanted. As Isotexas describes.
If they were all engineers and they
wanted numbering and insisted on it, then I'd give it to them. But not first up.