The leader initiative test is optional and the choice belongs to the player. If it is not made, the units may perform actions according to 2.4.2 no orders section.
If attempted and succesful, the units can perform full orders actions.
If failed, the units cannot do anything but rally.
Thank you. That confirms my understanding.
I think it reflects the fact that as the army leader you may want to provide or change specific orders in reaction of the enemy moves. You send an enseigne that might or might not arrive in time due to the heat of battle. Or maybe that brigade leaders argue with the orders resulting in no move at all. When you do not attempt the test, decisions belong only to brigade leader which are limited as it has not a full vision of the battle and the general strategy plan.
Let me see if I can clarify what I meant by "gamey":
I find the optional nature of the leader initiative test a push-your-luck game mechanic that doesn't belong. The choice to take the test or not does not (that I can see) map to any decision being made on the battlefield. It would make more sense to me that a formation that hasn't received orders *has to* take a leader initiative test and design the test mechanic to have three possible results: pass (effectively gaining Received Orders status for this activation), partial failure (the constrained actions listed in 2.4.2), full failure (rally only).