Not convinced by this mechanism. If I had a large stack with an inactive leader I shuffled it so that an active leader was in charge, if necessary removing the Corps or Army commander and attacking with his sub-units. With a Division, I detached the leader and led the constituent units make the attack. I don't understand why inactive leaders can't form Divisions either ('Don't assign troops to me now, I'm having a nap').
Surely you should just give a leader orders without 'knowing' if he is 'active' or 'inactive' for the next turn. Perhaps then a record should be kept of whether he was 'inactive' so that when you review the turn results you can understand why an order was not carried out.