I have no experience with dogs, but if you are looking for a positive reinforcement based solution, maybe you could ask Brenda
, who also has Border collies. I don't know much about her interaction with them, but when it comes to horses she is such an inspiration in terms of training in a very systematic, purely positive way, so I guess it will be similar with her dogs (you can see some videos in her dog video channel)
. Unfortunately, she does not write here anymore, but perhaps you could simply send her a PM.