Sorry, but all this wiki and the manpage seem to gloss over the most obvious question:
What happens when you commit conflicting edits in different repositories?
You get a regular git merge conflict, which can be resolved in any of the regular ways, except that conflicting files are just symlinks.
$ git pull
CONFLICT (add/add): Merge conflict in myfile
Automatic merge failed; fix conflicts and then commit the result.
$ git status
# On branch master
# Your branch and 'origin/master' have diverged,
# and have 1 and 1 different commit(s) each, respectively.
# Unmerged paths:
# (use "git add/rm ..." as appropriate to mark resolution)
# both added: myfile
no changes added to commit (use "git add" and/or "git commit -a")
$ git add myfile
$ git commit -m "took local version of the conflicting file"