"Baleros was a continent unique in that despite there being nations and countries and kingdoms and so on, much of the fighting was done by mercenary groups, ranging from smaller troops like the Raverian Fighters to huge Companies comprised of multiple regiments of soldiers who were almost constantly embroiled in conflict."
The companies active on Baleros are like nations themselves. There are countless companies who have their own cities and towns where they base themselves. They have contracts and earn income from protecting places, and they send out their own armies to fight. The big ones have influence, representatives in other nation, even entire merchant organizations that cater only to them.