I really don't understand your logic here. Perhaps you don't understand what a cadaver dog is trained to do. They don't just locate dead remains, They find the scent of dead remains in the air and follow that scent to its most concentrated point... which may result in a body being found or may result in a place where that body was before it was removed, which in turn may reveal evidence that points to a suspect.
For example, say a dead body was taken out of the trunk of a car and dragged or carried to a spot in a field where it was left, but later the person who dumped that body got nervous the body would be discovered, so they went back to the body, and threw it back in the trunk to be moved elsewhere. The dog would find the scent "cone" in the air and track it to the spot where the body was dumped. The dog insists this is where the body was, so the search team digs thinking the body must be in the ground... but find no body. This doesn't mean the body wasn't there, only that it HAD BEEN there but moved in such a way that the scent couldn't be followed. What the dog found was the most concentrated area of scent. The dog handler knowing this is the most conentrated area of scent knows by the dog's reaction that the body WAS there but had been moved. So the team checks around the area and finds tire tracks that may lead to identification of the car used to transport the body. Or in the dirt they find tiny scraps of decomposed material like skin or blood. They can take samples of the dirt and find that there is a high concentration of decomposed material that proves a body lay in that spot decomposing. Now they have other leads they can use like checking the shoes of certain people to see if they can match dirt or other seeds/grasses that show a certain person was in that field. They can also check whatever is on the shoes to see if there is any decomposed dead body material in the dirt or other seeds/grasses on the shoes which would identify who it was that dumped the body and/or retrieved it again to dump somewhere else.
This is how ALL dogs scent whether they're tracking prey, live fugitives on the run, dead remains, or whatever. But specialty trained dogs are dogs that have a highly developed scenting ability plus the desire to follow a particular scent without being distracted or giving up. The rest is pretty much just the training to respond to signals from and handler and give the handler signals of a find.
