It depends how big the document is, i.e. what is the density of users per page. If it's a 100 page document and the 100 users are all working on different sect

It depends how big the document is, i.e. what is the density of users per page. If it's a 100 page document and the 100 users are all working on different sections, then it could easily be possible. I just don't remotely see a use case for this. Real-time human collaboration in general fails at a scale much smaller than this, and not because of the tools available.