What do you make of this, "....the clash of two modern armies [is] one huge battle spread over space and time, in which the smaller battles fought by the army corps...[would] form the tactical encounters of traditional battles. These large numbers of battles that would take place far away from one another as the individual corps or groups of corps came into contact with the enemy would be welded together by the commander-in-chief into a 'complete battle'. The individual [smaller] battles would be given significance by the commander-in-chief's plan. Just as a commander of old gave units particular goals on the battlefields of days past, a modern commander-in-chief would give specific goals to his army corps. Each would play a part in the overall plan. 'The success of battle today depends more upon conceptual coherence than on territorial proximity. Thus, one battle might be fought in order to secure victory on another battlefield." 'German Strategy and the path to Verdun, Erich von Falkenhayn and the development of attrition, 1870-1916' by Robert Foley, P. 66. Most of it is a paraphrase by Foley with some quotation of Alfie Schlieffen taken from 'War Today' in another Foley effort 'Schlieffen's Military Writings', pp 198-201.  

 I have the impression that the 'operational space' in the Great War was rather narrow, being the thin line where corps could manoeuvre under covering fire from artillery and machine guns, either side of no-man's land (until one army was too weak to contain its opponent). The German 'elastic' method after linear defence was overwhelmed by the Entente's material superiority was intended to create an encounter battle, with the Germans having home advantage, yet the British confounded it once Plumer got his way. Motorisation, wireless, aircraft etc in the 30s and 40s widened the operational space, at times to several hundred miles rather than several hundred yards but then again much of the fighting (and most of the decisive fighting) in WWII took place over the same distances as in WWI.