Ashes introduces the concept of a Meta unit. When a player forms an army, all of the units in that army behave as if they are a single unit. Selecting one will select all of them. Each unit is aware of every other unit in its army and automatically engages enemies and protects allies based on the needs of the army. When someone forms an army, each child unit is effectively just part of a single big unit that can and should be controlled as such.