I haven't seen this gentleman mentioned on this forum, but maybe he is and I just haven't wandered onto those threads. Wondering if anyone here has had the pleasure of working with him? He apparently had to put his dog down (Fury) due to training injuries at age 7 (I think that's the age he states in the video).
Overall this video seems like good info to me:
robertcabral.com
Full disclosure: I am not Robert Cabral - but everyone has figured that out long ago : ))
Overall this video seems like good info to me:

German Shepherd Breeders - The Good the BAD and the UGLY | Avi Cohen EP.80 - Robert Cabral
The truth about breeders can save you a lot of heartache when it comes to getting a puppy. Too many people won’t tell you the…

Full disclosure: I am not Robert Cabral - but everyone has figured that out long ago : ))