Don't give up on the dog, a dog that is trashin on armadillos is a dog that is HUNTING, the war is already won if you get your hands on a dog that naturally goes out and hunts, you just have to figure out how to fight the little battles to clarify to him WHAT you want him to hunt.
I personally am a firm believer in the saying " a trashy dog is a hunting dog without refinement."
Just my opinion of course.
X2... turn him loose on fresh hog sign or to the bat