My first sign that KC was a natural at herding was when my Huskies broke out of the kennel and she followed them. She ran my male sibe down from behind, cut him off at the property line and worked him back up to a corner where I could snag his collar. She did this ALL on her own. I saw them a few seconds after they got out and KC just did her thing with no commands whatsoever from me. I have never been able to figure out how the Huskies fit through the fence much less KC. I have had 4 of my 5 Shepherds to "Sheep Meets" where they were evaluated but not officially tested but so far KC is the only one officially tested. All of them did well and really enjoyed it.
Even if your dog lacks confidence I think herding could help him improve in this area as long as it is done correctly taking into consideration his temperament.