Hello Brother! Yes, we've used those... sadly they don't work "at scale." My department has 600 members and a lot of them have good ideas. They have to go through the chain-of-command to get those ideas heard. This method not only suffers from the telephone problem Ie. the idea is lost in translation. It also suffers from a Chief or Capitan not liking the idea(s) and never doing anything with it. Manuals and SOPs in a democratic environment where anyone could clone, make changes and submit pull-requests would be a manna from heaven.
In that case a Github wiki might be a good start. You get the version control, but there's enough abstracted away that it should be easy to get up and running with. Now, you just need everyone in your department to get a Github account...
Have you all tried using some of the features built in to the editors like revision tracking or history a la google docs?
I know I'm starting to go apples to oranges here- but just tossing that out since those features are sometimes overlooked or forgotten about.