Measure twice and cut once. Sometimes not remembering to do that causes trouble, and has sometimes ruined some beautiful wood stock.
Frequently we do something similar in the Task Server environment when we forget to check the collection references that our tasks are assigned to. Like sending a Shutdown, or Restart task to "All Computers".
While this won't be painless to all end users, we can mitigate it and stop it from hitting everyone, using the following procedure:
It's just that simple. And while it won't be painless for you as the Altiris Admin, at least not all of your users have to suffer.