[unlaxedneurotic]

How often would this kind of report writing, which may involve many reporters, happen in an org like that? I don't think someone would like to invest in training and tooling for something that might happen once a year.

[p-e-w]

All the time? Such institutes push out 300+ page reports on a regular basis. Do you think those are written by a single person?

[7steps2much]

While that is true, one could argue that these reports are either split into distinct parts written by individual authors or are not written in parallel.

A report doesn't have ten people writing the same page. If everyone writes a chapter then merging is trivial. No need to learn a complex tool

[vertere]

For drafting yes, but at some point someone will probably want to edit or review the parts collectively. It's easy to prematurely consolidate the chapters into one file, and then any further changes have to be merged into the 'master'. A proper VCS can help here.