Danny, Arkansas soldiers have always been difficult for me. The information was copied as carefully as possible.

I'm not a large fan of Wikipedia but they offered the following "Morgan's Battalion was increased to a full regiment and reorganized as the 26th Arkansas Infantry on July 23, 1862, at DeValls Bluff, Arkansas. This unit served in McRae's, Cabell's, L. C. Gause's, and Roane's Brigade, Shoup’s Division, First Corps, Army of the Trans-Mississippi. The field officers were Colonels Asa Stokely Morgan, F. P. Yell, and Iverson L. Brooks:[4] Lieutenant Colonels James P. Stanley and John C. Wright; and Major Samuel Gibson.[5] The unit was composed of volunteer companies from the following counties"

Compiled Military Service Records seem to indicate his name was Iverson Lee Brooks or Brooke and that he was with the 3rd Brigade with the rank of Captain on page 16 of his CMSR's.

I would suppose the surgeons only knew what was told of the soldier having said that I'm sure errors occurred at times.