Before revision: While there were a significant number of EAC in WWII , with increasing power of smaller organizations, it may not be required to have a ground force of the size of: Field army, made up of two or more corps plus units under the direct control of the army commander Army group, composed of two or more field armies plus units subordinated to the army group commander Theater, composed of all land, sea, and air forces in a geographic area Even in WWII, while the Western Allies used these terms, they were not universal.
After revision: While there were a significant number of EAC in World War II , with increasing power of smaller organizations, it may not be required to have a ground force of the size of: Field army, made up of two or more corps plus units under the direct control of the army commander Army group, composed of two or more field armies plus units subordinated to the army group commander Theater, composed of all land, sea, and air forces in a geographic area Even in WWII, while the Western Allies used these terms, they were not universal.