Putting aside the horde armies, yes, some players deliberately create 'break inflation' brigades to sit at the back and watch the fight. But it can be high risk because any decent opponent will target them ruthlessly as they are always rather squishy. So the counter to that sort of deep strike is to protect them with something harder, but that has to come from the main fighting force thereby reducing the combat power at the front. That said, the WMR optional Scouting Rules mean that sometimes the 'light forces' have already achieved their mission by the start of the game? Overall, it's something that you do see quite a bit, but it doesn't seem to cause much of a problem in terms of game balance.
