Granted, I prefer cropped and docked, but I find it hard to believe that a "bad guy" confronted with a mouthful of Doberman coming at him is going to think of grabbing the dog's tail....
Well for one thing you would be surprised, if a dog grabbed hold of my arm I would attempt to screw it's ears off of it's head quite literally whilst kicking it as hard as I can in the rib cage under its forelegs, you would be surprised when nature kicks in and survival instinct is paramount.
K9 take downs don't always go like in a Schutzhund trial, the sort of people dogs are actually used on are not nice citizens like you and I, chances are these days, round here anyway, they will have a blade on them, better than teeth.
The tail is more for multiple attackers yes the guy getting bit is unlikely to pull the dogs tail but his buddy(s) certainly could.
A sufficiently strong and determined human could easily swing a dog by it's tail into the corner of a wall and break the dogs spine.
A dog isn't a particularly useful tool against multiple attackers with really bad intents.
Perimeter, PP and security dogs get killed.
A human being can be equally vicious and equally effective a killer as any dog.
They are far more effective against students and protesters than hardened criminals.
Asmit has already answered the GSD,Mal situation.
Fact of the matter is that this is why dobermans are traditionally cropped and docked, there is no argument for or against it.