You will find that the records are confused because of a special circumstance involving "Hardy's" regiment. Officially after the Battle of Arkansas Post those soldiers of these regiments who were not at that battle were designated as the 19th/24th Arkansas Consolidated and is listed in the Table of Organization of the Confederate Army as such in the Battle of Jenkins Ferry. However it was more commonly called Dawson/Hardy's regiment.

However, those members of the 19th And 24th Arkansas that were captured at the Battle of Arkansas Post and exchanged at City Point, Va. in April 1863 never returned to Arkansas to be reunited with their parent regiments but were also consolidated and designated as the 19th and 24th Arkansas in the Army of Tennessee.

Because of this identical designation when the muster rolls were compiled there was much confusion about which 19th/24th Arkansas Infantry a soldier served in. Therefore you may want to check the muster rolls of the Army of Tennessee 19th and 24th Arkansas and see if your soldier appears in those rolls by mistake.