Benning, as the reserve of Hood's/Law's division, and McNair, as the reserve of Bushrod Johnson's division, attacked at nearly the same spot on the 19th of Sept, 1863, though the Georgians moved forward later; the row of Georgia regimental stones and the N.C. marker of McNair's are practically in line. I agree, there can probably never be a decifering. On the 20th, Benning again followed McNair's path, but with better results. As to the chaos in the west Viniard's field on the 19th, I offer:
"I was... [sent to] the firing line [as]... our forces in front of the Widow Glenn’s house were making a countercharge, and... some 200 or 300 Confederates found themselves enveloped.... For a moment I was at a loss to know whether I was captured or whether my Confederates were.... I quickly solved the uncertainty by spurring my horse and galloping into their midst and yelling at the top of my voice, “Surrender you devils! Surrender!” It was a most ridiculous thing to do, [but]... to my great surprise & immense relief, the Confederates dropped their arms" - Yankee Pvt. John Davis, 15 PA. Cav., Rosecrans’ escort Kirk, 241
The Federals did have Barnes, Buell & Harker, and then Bradley's brigades all sequentially slam into the Rebels' left (southern) flank during that time, and so they may have held an advantage, particularly in recapturing their lost artillery. Joe