They often do have version and revision numbers. As well as final release numbers. I find the biggest issue is the lack of ability to trace the document forward

They often do have version and revision numbers. As well as final release numbers. I find the biggest issue is the lack of ability to trace the document forwards in the repositories. Usually an update will list which documents it updates but often it's much harder to find if there have been any new updates that have further obsoleted this update.