If a ship encounter chance for a nation is not defined, then it is assumed to be MAXIMUM! So either we have to swap that around in code or Sweden must be set to zero for every ship. As for making Swedish ships less common, that will be a tricky one. The game first decides the nation and then decides the ship, so the encounter chances will not help. So we'd have to influence that first decision, which is probably repeated in various spots and forms throughout the code. But if that IS done, it could be made a more common function. With that, it would become feasible to make the chance of a nation depend on the number of colonies they have. So capturing colonies would then have an effect on the nations of the ships you encounter. Could be cool!