Yes, both the Miniature Pinscher and the Doberman [Pinscher] are related. The Miniature Pinscher was developed by breeding small strains of German dogs (including the Pinscher) together. The Doberman...
If you mean as in give birth to a schnauzer, then no. Even if you bred the min. pin. to a schnauzer, the babies would be mixed breed and would not be classified as a pure breed schnauzer.
If you mean...
Their correct name is Miniature Pinscher. The Doberman is a newer breed than the Min Pin. They are not even related. To answer you question, yes. Any dog can mate with any dog. A Saint Bernard can...