I had GSDs for years and honestly it is going to come down to the individual dog and the amount of prey drive your dog has plus how much work you want to put into it. I have had German Shepherds at both ends of the spectrum and would never, ever trust some of them unsupervised despite the amount of training put into them(I did obedience and conformation). I had two that I could have left unsupervised in a coop and they wouldn't have done anything more than let the hens walk all over them. They are amazing dogs
Keep up the good work with yours, I hope the training sticks.