Here are 3 but not sure who your man might be, would need more info on his activities and whereabouts during the war to determine which regiment. There was no Thompson's Arkansas Regiment but there was a Missouri STate Guards regiment commanded by a Thompson and refered to that. Many of that unit are buried in Fairview Cemetery, Van Buren AR. Could that be the "state troops" refered to? If so the second man might be him.

Anthony

Maddox, George W
Private—Enlisted in Co. K, 3rd Arkansas Infantry, at Hamburg, Arkansas, May 20, 1861; no record after October 31, 1862

MADDOX, GEORGE A. Pvt - Enl Co L 7th Ark Cav 31 Nov 1863. Trfd from Thompson's Regt 30 Nov 1863.

MADDOX, GEORGE Pvt - Enl Co D 4th (Gordon's) Ark Cav 10Jun1863 at Clarksville, AR. Present through Oct 1863.

Also a George Maddox in Quantril's Raiders