Well yes, the germans have always been superior breeders of all working dogs. To tell the truth, they use absolute zero emotion when it comes to dogs. When they are working up a breed, if it don't cut it it's culled. They have no time for faults.
But that's neither here no there. Bejay is a perfect example of Americanized hunting with dogs (not a slam, just the way we have been doing it for the since WWII). Airedale used to be the most popular dog in the country by a wide margin. This was greatly do to their versatile abilities. Since WWII it's almost impossible to find a good hunting airedale. Even here in the US, farm dogs would pull double and triple duty as hunting dogs, stock dogs and protection. We've become specialized, so have out dogs.
Why would a rabbit be less desirable than a quail? See, over there, when they go hunting they aren't rabbit hunting, they aren't quail hunting, they aren't varmint hunting, etc etc. They just go hunting!! No, they don't have a certain command they use with their dogs to get the dogs to hunt one game one day and another game the next (even though I'm sure some have done it and it's possible). Their dogs may run hare, birds or varmints all in the same hunt. If they want to avoid a certain game that particular day they avoid areas that hold that game. They also maintain strict control of their dogs and are able to call them off of game that they may not want at that point in time. If they want hogs they call them off of game other than hogs. Also, dogs get real good at picking up on intended game just by the type of cover they are hunted in. A buddy had a hound that could be run on daytime coyote but would only run coon at night. When we take dogs out a night we can walk out in a field and the dogs head for timber.
Take my Jagdterrier. I can take her out hunting anything. I can call her off rabbits if I'd rather be yote hunting. I can call her out of a hole if I prefer to move on. I've never used her on pheasant (I hunt furry critters, not feathers), but I'm sure she would be great at it and I can control her 100% of the time. Over all, when I leave the house we may chase squirrel, coon, rabbit, fox, opossum or coyote. I never know from day to day, min to min. There's nothing I hunt (cept deer, not legal with dogs) that I won't sick her on.
LK