I too agree with Allen, but the South did with what the had. When Van Dorn issued the order to supply the regiments with long range arms, it did not say where to get them. I have not found any issue of such weapons, but the practice and training is defined. Cozzen's book also notes several instances where Southern Sharpshooters helped the cause.
Cozzens noted the Northern Sharpshooters with a few references. One was of poor character and one with others with effective use. The 64th IL was not given good marks. We know what the 2nd and Stirmans and maybe Rapleys units did, and here I seek to find about others. Cozzens wrote of Sharpshooters as something he addressed on the margin. He did not get into detail.
Late in 64 during McCook's raid the 6th TX Cav did come up with Sharps rifles, but not enough ammunition.