on the task at hand, and avoided the rivalries as much as possible. Despite this approach, he was still involved in controversies with the other functional commands, including an ongoing rivalry over allocation of the best qualified recruits and draftees. Personnel recruiting and training Training McNair organized and supervised instruction in basic soldiering skills, to help individuals become proficient generalists prepared for more complex unit training. Once individuals were qualified, units carried out collective training, beginning with the lowest level, and continuing to build through successive echelons until divisions, corps, and armies were capable of carrying out large scale simulated force-against-force exercises. He insisted that training be conducted in realistic conditions, including the use of live ammunition, or simulators that replicated live ammunition, so that soldiers and commanders would be prepared to fight once they deployed overseas. National Guard McNair had difficulty implementing a training program for National Guard units, chiefly because of their lack of prior military experience other than monthly drills and short annual training periods. He recommended a wholesale demobilization of the National Guard; Marshall and the Secretary of War disagreed, partly because they anticipated political backlash, and partly because the manpower they provided was in demand. McNair also found National Guard senior commanders wanting; in his view, National Guard officers should not progress beyond the grade of colonel, and professional full-time officers should command at the division level and above. In this, he was mostly successful; all but two National Guard division commanders were replaced by regular Army officers, and most National Guard generals carried out stateside assignments, or non-combat overseas assignments. Some served in roles below division commander (such as assistant division commander), or carried out administrative and training roles, such as provost marshal or school commandant. In addition, some accepted reductions in rank so they could serve in overseas assignments. Fielding army divisions Original War Department estimates called for the Army to raise, equip, train, and deploy as many as 350 divisions. Later estimates revised this number downward to between 200 and 220. One factor that enabled this downward revision was that U.S. divisions were better equipped in some areas of their organizations than those of their adversaries, particularly later in the war; for example, every type of U.S. division was completely motorized or mechanized, while equivalent German divisions often relied on as many as 4,000 horses for transporting soldiers, supplies, and artillery. A