An unexpected bonus of the lack of farm labor was that in essence the Confederacy had a "scorched earth" policy in AR. The only successful defense the Confederates made anywhere in 1864 was in the Red River Campaign, and that success was primarily due to logistics--a large Union invading force (even Steele's smaller force) couldn't find enough forage and food to supply itself. And wagon supply was chancy at best. This evened the odds for the Confederates, who, as I said, fell into this unplanned "policy".
To paraphrase a European military expert, in 1864 AR a large army starved, and a small army got beat.