I'd bet most dogs with a modicum of prey drive could be used as ranch dogs. There's one or two reports of Tollers being used as chore dogs. The majority of farms are hobby farms with neither the numbers nor the wildness of animals to merit a true specialist.
So while there is little tending going on any more, because places where it's feasible don't have the numbers and places that have the numbers don't have the geography or the tradition, German Shepherds are a perfectly valid choice if you need a dog to move some animals around. I know a farm that has used WGSL on hogs. However, I suspect any large, brave dog could have accomplished the same tasks.