Re: I make an exception to houserules when...
I have to be honest i don' t follow them for the full 100%. To give you one example i retrain my legions when thy are near Italie. But on fighting battles and reloading the game i am very strict. If i loose one because of the reason you just mentioned i keep playing. But i understand your point because it is very frustrating when the AI get' s in to action when you think you swithced them off.
One tip on this look to the enemies troops before you turn of the reinforcements box.