The manpages for GNU utilities are usually stubs that essentially say:

  The full documentation for XY is maintained as a Texinfo  manual. If
  the info and XY programs are properly installed at your site, the command
  
          info coreutils 'XY invocation'
  
  should give you access to the complete manual.

(This is, btw, one of the best reasons to love the BSDs.)

This wouldn't exactly be a great training project for a technical writer since the content is essentially there and would need to be transformed into decent manpages. This is, however, an open source project that could use documentation help, and one with unmatched popularity, so this might be interesting for someone else who would like to acquire experience with open source documentation while doing something that lots of sysadmins will appreciate.