Sylvester B. Scribner, Confederate soldier from Virginia

There are three Confederate Civil War soldiers named Sylvester B. Scribner listed in the rosters as having served for Virginia. One enlisted into the 3rd VA Infantry in 1861 (he died 4/18/1929 and is buried in Richmond, VA.), one was drafted into the 18th VA Infantry in 1864, and one served in the Confederate Signal Corps, no dates. I am trying to ascertain if these were all the same man which is entirely possible given the circumstances at the time.