User-based metrics VS. RTH-based metrics

Content

I manage a team of sourcers who provide candidates to the recruiting process, but don't actually manage the candidates in the process. I've had some difficulty identifying metrics that I can use to measure their work - all of the reports we pull now are based on RTH metrics (TTF, Source, etc.), but I want to get some other metrics that would include things like # of candidate records created, # of notes added, # of candidate status changes, etc.

What user-based metrics do you use?