Too many variables to define range. These days with the garmin, just ask how far out the dog hunts and decide if that is short, medium, or long, to you.... As you have already found out range in a dog changed with terrain....why wouldn't the definition of range change between regions?
X2 IMO,
I think it all depends on the size and terrain of the land you are hunting and your hunting style. A dog hunting out 700 yards would be worthless to me because I hunt a lot of smaller properties, and alot of times its on foot. It would be almost impossible for me to keep up with the dog and keep it on the property i have permission to hunt. Especially if we got on a runner.

So i would conisder that a long ranged dog.
But the dog may also be worthless to someone hunting a big, open ranch in West Texas, because they dont think the dog is covering enough ground, therefore being considered a short or medium range dog.
So like Chris said, Too many variables.
