Question about mercenaries

Hi. I want to preface this saying that I've finished light novel.

The question is simple. We know that some rogue sword saints can appear among smugglers. We also know that Boreas family can afford sword kings, along with other families. So why does heir to the throne, such as Ariel, has only advanced sword fighter Luke as her bodyguard? Why doesn't she have some at least sword saint or sword king in her ranks? If they are paid with one gold per month in Boreas family, surely she can afford one to handle her safety in foreign land such as Sharia. Am I missing some context?