Section 13-403 - Assignment to divisions, brigades, and other tactical units(a) To maintain an appropriate organization and to assist in instruction and training, the President of the United States may:(1) assign the National Guard to divisions, brigades, and other tactical units; and(2) detail officers from the National Guard or the United States Army or Air Force to command those units.(b) A commanding officer of a complete unit organized in the State may not be displaced under this section.