If the information about these men living in Telfair County GA and their ages is correct, then neither one ever went to Tennessee during the war. John Wesley Walker enlisted on May 15, 1864, some time after he supposedly died. Both Walkers survived the war, and pension applications made to the State of Georgia in their names.
Very little family information is "provable". I would be surprised to learn that National Gravesite Locator data is provable. In cases where conflicting evidence exists, it's best to consider the facts and settle on what makes the most sense to you.
When I read your post about two Georgians dying in Tennessee in 1863, it immediately raised questions. Very few Georgians served with the Confederate Army of Tennessee at that time, so I immediately doubted the information.