Hmmm. What an interesting thread this is turning out to be. :-)
With regards the problem, how about this one. Divide and conquer. hobbit-alerts.cfg supports "include" statements. The config also doesn't get grumpy if we have 2 instances of the same server with the same tests and different email alerts. You could then have this in the file include /path/to/alerts-teamX.cfg include /path/to/alerts-teamY.cfg include /path/to/alerts-teamZ.cfg Permissions allow each team to edit their own files, and each team is then responsible for ensuring their shifts are updated correctly.
Each team will then have their own version of hobbit-alerts.cfg, which will then be merged by the includes. This still allows you to use the mechanism Henrik proposed earlier within each team config file, but also gives each team a simpler, team-centric config file.
Of course, this doesn't exclude the possibility of somebody writing a nice editor :-)
Cheers V