I don't know about the page numbering. I have to a similar exercise to produce our club bulletin for which I posed a question somewhere on here a little while ago. The compiling is done with Office Publisher (which I discovered I already had on a pc acquired in a flat clearance!). Publisher, or at least the 2007 version I have, doesn't want to know pdf. LibreOffice doesn't want to manipulate pdf either in my experience (although I might well be missing something) but it will open them as a sort of image file which can then be saved in odt or doc (I think I use doc) to be compiled in Publisher. As far as I remember I have to use PDF CReator (a virtual printer) to create the finished pdf. Only question is whether Publisher will do page numbers.
Note there is PDF Architect which should do what you want perfectly and comes bundled with PDF Creator if you are not careful. You need the subscription modules and I found the editor to be very mercenary which is why I stopped using it (which didn't stop them still taking an extra 85€ off me when I didn't pay attention to unsubscribing from it).
I do also have Scribus for this job but it has a learning curve which I have not got very far along (question of making it find the docs you want to use, the rest looks relatively straightforward)