If Im wrong please tell me, it appears from the posts that some have been very stable and that is good, especailly with family members
you are wrong!

buy from good breeding(german as you said) and then train as you would any other dog(protection or not). the only difference between training a big dog and a little dog is one takes 2 hands on the leash and one takes 2 fingers
do not be fooled by the size of the dog. a small dachshund male is every bit the man a 95lb g shep police k-9 is and is capable of of the same behavior, both in fighting drive and obed., relatively speaking of course.
the mini schnauzer is a joke as they have been relegated to the armchair decoration for far too many generations.
their are some good german lines but next to impossible to find in this country.
the major poblem with a dachs is to see that they get plenty of field exercise for strength and endurance and keep the weight off them. their back has to stay in great shape, like iron, to avoid injury.
the other problem being it is really hard to tell if they are sitting as their butt only drops 1/2 an inch .

People sleep peaceably in their beds at night because rough men stand guard around the world ready to do violence on their behalf!