I've cross-referenced Bryan Howerton's roster at the Ed Gerdes website with that provided in Gammage's book and excerpted those soldiers of Company "I" listed as "Left in Arkansas". This list shows the names as they appear in Bryan's roster with his comments taken from the CSR's and then lists the names from Gammage's roster. I don't know if this will help, but it does show that most of these "Left in Arkansas" soldiers have no information other than their enlistment date.

Names from CSR's Remarks (if any)from CSR's Gammage's List
ASHFORD, J.A. ASHFORD, G. A.
CAGLE, J.F. Sick in hospital at Van Buren, AR 28 Feb 1862. CAGLE, Joseph
CECIL, JOSEPH Furlough 10 May 1862. CECIL, Josiah
DOULTON, W. D. DALTON, W. D.
HADAWAY, JOSIAH HADAWAY, Josiah
HASE (HAYES), A.Y. HASE, A. Y.
HOWELL, ISAAC P. HOWELL, J. T. (Isaac P.)
JACKSON, GEORGE Discharged 17 Nov 1862. KNIGHT, J. R.
McBROWN, LOUIS Present 29 Feb 1862. McBROOM, Lewis
McCLAIN, W. J. McCLAIN, W. J.
NICHOLS, BERGES Died 1 May 1862. NICHOLS, Berges
NICHOLS, LAFAYETTE Died 26 Mar 1862. NICHOLS, Lafayette
NOT LISTED OLIVER, W. P.
REIKER, HENRY REIKEE, Henry
RUSSELL, SAMUEL RUSSELL, Sam'l
NOT LISTED SCOTT, J. F.
SHEPARD, EDWARD SHEPPERD, Ed
STINNETT, BENTON H. STINNETT, B. H.
TOWREY, ED L. TOUREY, E. L.
TOWREY, JOHN H. Present 31 Oct 1862. TOUREY, John
TOWRY, JOHN Discharged 17 Nov 1862. TOWRY, Silas
VOILES,JOHN VIOLES, John
WALLACE, J.P. Died 6 Apr 1862. WALLACE, J. P.
WINTON, GEORGE M. WINTON, G. M.
WINTON, ISAAC Discharged 17 Nov 1862. WINTON, R. B.