True, but it also worked way better gameplay wise with the old map system. It was always tense when you and your neighbour had amassed armies at the border, knowing that the AI will most likely invade as soon as you leave the province undefended. You couldn't just ignore them and keep your province safe with a free upkeep levy, since the AI would invade full force with the simple risk map instead of the micro stack drag the series has been plagued since. And economic damage was done anyway even if you still held the castle. Instead of endlessly grinding the AI down, you had decisive battles.