A bit more meat on the bone......
Firstly just the bit about 'miniature' or 'zwerg' - personally I wouldn't choose a mini for stalking, yes some use them and they are happy, but personally I think that any amount of deep bramble/bracken/heather would cause unnecessary problems with the shorter legged variety. Yes they will 'hunt' under any of that with ease - but 'walking' over, on lead is a different story.
As tracking dogs - when trained correctly and given plenty of experience, they are and can be very, very good. The combination of a great nose and a very tenacious nature keeps them going when others might give up - and I am talking old cold trails here - not 20 minute/50 metre death runs. The biggest challenge is the distraction of fresh/hot scent that has contaminated your dull cold trail. Let's be totally honest, another challenge can be their size - even standards. We have a large football-pitch-sized reedbed on our stalking ground, very thick sedge and knee deep, up to waist deep, water. A GWP might power its way through - a teckel will struggle. But the flip-side on the size is a neat little dog in the car and in the house.
As a stalking dog..........It can be done, indeed I will be training my current pup - the litter sister to Rattens pup - to stalk and be a highseat buddy more than a tracking dog. Probably, if all I wanted was a stalking (on foot) companion - I would probably buy a Lab.
As far as training is concerned - pretty much all dachshunds/teckels are clever dogs - smart enough to second guess owners and smart enough to outsmart some owners. When it comes to prey drive, 'some' are off the charts - our first two German imports are too much really. I admire their spirit greatly. They were just born and bred to hunt and given the chance they would hunt anything. We have experimented with breeding from them and found that a dash of show blood in our second and fourth litter took that edge off. We have three others from Scandi/Italian dominated lines and they are easier on the nerves - that said.......they still have incredible noses and plenty of poke. Horses for courses.