g. Reinforcements. All Soviet (except for UR/MG units) and Axis
reinforcements enter the map and move during their respective
friendly Movement phases. Soviet and Axis non-motorized, orange
MA and green MA combat units, MSUs, and Supply Dumps
can only enter during their respective Movement phases.
Since Soviet orange units can only move in the movement phase (not motorized movement), the arty unit should not have entered and moved until after combat.
In reality, it made no difference in the example, as it wasn't involved in combat.
(The eastern front games often have small errors in the examples, the one in AGN had to be completely rewritten in the errata due to so many errors!)