As confederate in my last game vs. IA, I had in 1863:
Army of Potomac near Santa Fe,
Army of Shenandoah in MA theatre,
Army of Mississipi in New Mexico ... etc.
This is a claim not important in game mechanic, but in game historical I would to choice the correct name for every army.
by wikipedia:
Armies and prominent leaders
The CSA was composed of independent armies and military departments that were constituted, renamed, and disbanded as needs arose, particularly in reaction to offensives launched by the Union. These major units were generally named after states or geographic regions (in comparison to the Union's custom of naming armies after rivers). Armies were usually commanded by full generals (there were seven in the CSA) or lieutenant generals. Some of the more important armies and their commanders were:
Army of Northern Virginia — Joseph E. Johnston, Gustavus W. Smith, Robert E. Lee commanding
First Corps, Army of Northern Virginia
Second Corps, Army of Northern Virginia
Third Corps, Army of Northern Virginia
Fourth Corps, Army of Northern Virginia, often styled "Anderson's Corps"
Cavalry Corps, Army of Northern Virginia
Army of Mississippi
March 1862 – November 1862: P. G. T. Beauregard, Albert Sidney Johnston, Braxton Bragg, William J. Hardee, Leonidas Polk, (also known as the Army of the Mississippi; redesignated Army of Tennessee on November 20, 1862)
December 1862 – July 1863: John C. Pemberton, Earl Van Dorn, (1863) William W. Loring (also known as Army of Vicksburg)
July 1863 – June 1864: William J. Hardee, Leonidas Polk, William W. Loring (also known as the Army of the Mississippi; redesignated III Corps, Army of Tennessee in May 1864, but continued to use its old name)
Army of the Kanawha — Henry A. Wise, John B. Floyd, Robert E. Lee
Army of Kentucky — Edmund Kirby Smith (Eventually commander of all forces West of the Mississippi)
Army of Central Kentucky — Simon B. Buckner, Albert Sidney Johnston
Army of Missouri — Sterling Price
Army of Middle Tennessee — John C. Breckinridge
Army of the West — Earl Van Dorn
Army of New Mexico — Henry H. Sibley
Army of the Northwest — Robert S. Garnett, Henry R. Jackson, William W. Loring, Edward Johnson
Army of the Peninsula — John B. Magruder, Daniel H. Hill
Army of the Potomac — P. G. T. Beauregard, Joseph E. Johnston
Army of Tennessee — Braxton Bragg, Samuel Gibbs French, William J. Hardee, Daniel H. Hill, John Bell Hood, Joseph E. Johnston, Richard Taylor
First Corps, Army of Tennessee
Second Corps, Army of Tennessee
Forrest's Cavalry Corps — Nathan Bedford Forrest
Army of Western Louisiana – Richard Taylor, Edmund Kirby Smith
Army of Arkansas – Sterling Price, Edmund Kirby Smith
Army of the Trans-Mississippi — Thomas C. Hindman, Theophilus Holmes, Edmund Kirby Smith
Army of the Valley (also known as Second Corps, Army of Northern Virginia) — Jubal Early
Some other prominent Confederate generals who led significant units operating sometimes independently in the CSA included Thomas J. "Stonewall" Jackson, James Longstreet, J. E. B. Stuart, Gideon Pillow, and A. P. Hill.