Carl and Tom,
I have a couple of ideas, but I thought it might help if I can round up some more facts before I take a shot at this one.

1. Does anyone have any idea when these unidentified men were killed? A date would be helpful.
2. If not, does anyone know when the stone was placed over their common grave?
3. Does anyone know if these unfortunates were southern or northern--or both?
4. Also, how do we know there were actually nine of them? Could there be more or less than nine?
5. If I read the message traffic correctly, we have no idea of these men's names then, right?

Incidentally, the Ham Brown Barn killing involved eight southern recruits, but the Union militia spared one as being too young at the urging of Miss Mary A. Brown, who lived there and hastened down to the barnyard and intervened to save any of those unfortunate men she could. Therefore, only seven men were killed. I should add they were captured under arms, but were then disarmed before the Union troops shot them. Sadly, such on-the-spot killings were authorized by then-current Union orders.
The Ham Brown barn killing took place 4 November 1864 near Four Mile Creek near Concord and west of Hatton in northwest Callaway County along the border with Audrain County, which is about 30 miles west of Wellsville in northwest Montgomery County where this monument is located. This leads me to doubt the Brown Barn killing is part of this Wellsville monument. I have other ideas, but I hope somebody can add more information before I jump in further.
Bruce Nichols