The dog who was handed off at the University was a Doberman. I was raised with Dobermans & terriers. My parents had a kennel. So that's what I went after when I had a home of my own. Sadly for me, we gained quite a reputation with my Dobers because aside from their amazing working prowess, they suffered genetic health problems & didn't live long.
But as you said to continue the discussion, I probably would not even if the training was sound for safety precaution's sake. The mind of the Dobe & herding breeds works different than that of the livestock guardian. My working dogs accepted if I said someone was okay... they were okay unless they turned stupid. My Pyrs would accept the person was allowed in my presence but they would not tolerate a stranger petting them or trying to tell them what to do. By very design, they're not really supposed to be easy with strangers. If they were the rustlers would have the cows, the horses, the sheep & be gone. The last vet I went to who didn't know me was going to give a rabies shot to one of my 2 Great Pyrenees. I finally offered to give the injection myself & he relinquished provided I could explain to him what he was doing wrong. When I explained what the boys did on the farm & that it's their job not to befriend strangers, he finally understood. I thought I was going to have to walk out because Buddy wasn't going to let him put his hands on him.
I have seen a couple of Kuvaz & Anatolian Shepherds who did well at the vets & in those situations but Bongo, one of the big male Anatolians wouldn't tolerate certain vet techs. If it was a different vet, forget it. I wish I had more experience with the other breeds you mentioned. I don't know what their capacity for learning & retention & reliability to the commands are. I've worked a couple of Black Russian Terriers & was told after I was the only stranger he'd ever seen his dogs warm up to. He handed me the lead half expecting me to get challenged. Then again, it's not uncommon for me.
For me safety for both dog & human is top priority & if I feel there is any question of if the dog will toe the line for the vet or his/her staff. Nope. They just have to deal with me.