There are 3 categories of herding dogs: cattle, sheep, and boundary/perimeter. Cattle dogs, which the GSMD fits into, are the Appenzeller & Entlebucher, the Rottweiler, the Bouviers des Flandres, the Australian Cattle Dog, the Pembroke & Cardigan Welsh Corgis, the Catahoula, as well many others. Two examples of sheep dogs are Border Collies and Australian Shepherds. Two examples of boundary/perimeter dogs are the German Shepherds and Briards.
Cattle dogs require power, strength, assertiveness, and conditioning, combined with a no-non-sense attitude and plenty of heart. This doesn't mean that they are unable to herd other types of livestock, it just means that the sheep and boundary breeds are not as well equipped as cattle dogs for moving cattle.
