Artificers were absolutely essential to keep an army on the move.
In Union Army a saddler / harness maker wore a hollow diamond sleeve patch.
Farrier with horseshoe patch on sleeve above the elbow.
Saddle maker insignia
U.S. Signal Corps sleeve insignia.
Army of the Cumberland Pioneer Brigade crossed hatchet sleeve insignia. He also has Veteran Volunteer sleeve flashes.
I realized that William Dublin was in the Confederate army, which did not have sleeve insignia indicting that a man was an artificer. However, there is nothing like a photo to illustrate a point.
A regiment when formed would have (+/-) 1,000 men. As I am sure that most of you all have noticed that (+/-) 300 men formed the battle line. From the first, regiments detailed men for service as artificers.
In many cases, craftsmen were detailed for the entirety of their enlistment. Saddle makers, harness makers, wheelwrights, farriers & blacksmiths worked tirelessly maintaining an artillery battery. It really was a rolling crafts fair with repairs & horse shoeing at every halt.
Every regiment in the Army of the Cumberland was ordered to detail men who had construction experience, axe men & other engineering skills. These men joined the Pioneer Brigade. As such they provided skilled craftsmen, supervisors & combat engineers.
The Signal Corps did not exist at the beginning of the war. As the Signal Corps was stood up mature, sober men who were educated were detailed to the Signal Corps. The signalists operated in (+/-) six man mobile units. They traveled independently as needed. Signal Corps officers were required to be University graduates. There were only 2,500 men in the Signal Corps, the bulk of those who served were detailed from regiments.
The Confederate artificers, signalists & specialists of all kinds are very hard to quantify. We know that saddlers, harness makers, farriers were detailed to perform essential services. The records, rather the lack of them, have frustrated scholars for over 150 years.
Hope this post gives you some notion of how William Dublin, artificer, would have fit into the greater scheme of things.