I'm playing around with Russia at the moment and decided, perhaps too hastily, to give conquering the central Asian khans a shot. Supply is currently at 2% in Khiva and my troops are suffering some pretty humiliating defeats at the hands of the Khivans. How do I increase unit supply? Railroads? Higher military budget? Is the supply system, and I fear this, the same as HOI3 i.e. supply being distributed from my capital across the vast plains of Russia to some far away land?