It was a pretty common occurrence in medieval times to start a war, buy an army of mercenaries, miscalculate something, not be able to pay them their salaries,

It was a pretty common occurrence in medieval times to start a war, buy an army of mercenaries, miscalculate something, not be able to pay them their salaries, get conquered by your own mercenaries. The conclusion people got from this was "make sure you pay your mercenaries on time", and not "don't start wars".