Here's my thoughts on it for what they are worth, I think some dogs are bred unsound, and for a reason and a job to be done.
Unfortunately the same drive we want backfires on us and why we want them.
I have an 8 yr old Russel, he's dodged the bullet so many times which i don't want to go into. After all these years i'm almost halfway there in having the dog I want.
He cannot mix with other dogs, he's had the chances to socialize, but will nail anything aggresive in his path.
His drive is what I wanted, but that cannot be calmed for love nor money, but is what makes him usefull