It would be very thin but so are some of the copperheads I deal with. I am into skin splicing to use short skins for bow backing so i am sure you could back a bow with smallmouth skins if you had enough that are pretty close to the same color.
Here is a splice on one of my short skin copperhead bows. It was invisible until I tried to enhance the color with a little leather dye. The dye soaked into the edge of the skin making a dark spot.
The reason I was using leather dye was one skin had two hourglasses that were completely without color so I drew them in with dye. Next I used the same dye on every hour glass to give me a good color match from one end of the bow to the other. The darker centers of the skin you see in the picture have been dyed with medium brown leather dye.