I don't know how much defense a single doberman could do against a pack of coyotes determined to make your smaller dogs into lunch. You run a pretty significant risk of losing the dobe too. Dobermans were intended to be personal protection dogs, meaning they protect YOU... not your dogs or your property. You may want to look into a different breed if that's something you're really dead set on. Maybe even a different species- I know many a donkey that would give a pack of coyotes a better fight than a single doberman.
Additionally my 80lb European male is actually smaller than my friend's 90lb American male of roughly the same age. Despite them both being roughly the same height, my dog is built for working and thus is more lean and trim to help him more with things like agility, speed, and jumping. I've known some BIG euro males but I've also known just as many smaller ones. The big dogs frequently have shorter careers due to the stress on their joints- too many muscle tweaks results in permanent injury and the added weight does not help.
Have you considered something more like an LGD? Most intruders will not argue with a dog bigger than them that looks alarmingly like a bear just came out of the house, and they are more suited to defending other animals from wild predators too.
Added by Editor--LGD = Livestock Guardian Dog
Jazi took the words right off my keyboard. For protecting your frenchies, an LGD would be more suited to the task. The Doberman is designed to protect their human in a direct confrontation, as well as alert to intruders and deter them. But they are not a dog designed to protect other animals, and they are not per se an estate dog.
Here is my opinion: I do not think you need a dog trained in personal protection. The expense that goes into acquiring a fully trained adult, or the money you'd pour into training up a pup is very significant.
It should be known that the key to personal protection is first and foremost in deterring. The last thing you want is an actual fight, so the most effective home and personal protection systems (be they an alarm, or a dog) work because they scared off any would-be attacker. 99% of the time a barking, snarling doberman will accomplish this and is an effective deterrent. A well bred doberman that has been selected with temperament in mind will accomplish this on instinct, and you can find dogs like this in European show lines, European Working Lines, South American Working Lines, American Show lines, South American show lines etc.
And actually for reasons outlined by GK, most ideal personal protection dogs in our modern contexts SHOULDN'T be dogs who's first instinct is to bite. They should only bite as a last resort. I would recommend finding out what the law is like in your state and municipality, as well as the liabilities involved with insurance.
The other 1% of the time when a deterrent won't be enough, will be someone who is either a professional who is well prepared and likely could take down most any dog (even trained) or so psychotic they have no notion of danger. There are very few people who actually warrant a personal protection dog that is also a trained bodyguard and not merely a scary companion.
Don't believe the youtube hype. There are a lot of videos that perpetuate or buy into the myth of Euro vs American.
By the way I've seen Jazi's dog in action, he is a perfect example of blended european show and working lines, selected for strong working ability and correct breed temperament, and he is indeed an ideal (imo) medium size, trim and fit male. And I've got no doubt in my mind that he would be a HIGHLY effective deterrent in 99% of cases.
Hell, my 65lb female makes the kind of face when she snarls that most people wouldn't want to mess with.
About the tail length... tails are docked at birth. Different breeders have variable lengths. You could always get it shortened at time of the ear crop depending on when the breeders does their selections, however I don't recommend it as the stitches are a pain even when just fixing the tails. I do know of one breeder who actively and intentionally prefers the shorter docks.