The idea that you can create a proud cut gelding by leaving the epididymis in the castration process and end up with stallion like behavior and physique is not backed by scientific data.
02 Stallion-like Behavior in Geldings - VeterinaryPartner.com - a VIN company!
This is another clear concise explaination. You will not find any published research that state otherwise. They're all written by DVMs as is The Horse article. I have never heard one of my vets (15 or more in my lifetime) promote that concept either in over 30 castrations.
So how did the vet come to the conclusion that he is proud cut?
I too worked in the Arab industry back in the early 80's in S Ca. They were breeding super hot horses but also in looking back, they were all poorly trained outside of the arena. I can attibute most of the behavior to the training and lack of socialization.