Hi Shawn,
Yes, that is currently the mechanism, and I agree it's not intuitive. It also doesn't track stats (e.g. success/failure percentage) for the nested jobs, or perform Notifications.
One issue is how to handle the log output, which currently ends up in Job A's logs. Would you expect to be able to navigate to job B and see only its output for a past execution that was triggered within another job? Or should it merely link back to Job A's execution?
We are also looking to modify the way jobs and workflows are defined. Essentially workflows would become independent of Jobs. This is a feature that has been on the roadmap for a while. (The way job references work now is that it essentially incorporates the workflow defined in Job B&C as if they were part of job A).