So the marshal can tell the Sponsor that the warchest is running low, so that the Sponsor can move to the nearest city to cash bonds before it runs out completely.
Which hassles two players instead of one.
Why not just give the sponsor the option to have it draw from his tax share instead? Something along the likes of "If warchest > X, then place Y% of the taxes into it". Or have the army maintenance costs stack like the trade balance does, and therefore get payed at the end of the week instead of beforehand.
