Ten men sworn to a brotherhood. Scattered. Hunted. Trying to find each other. This is why it works.
The found-family trope appears in some form in almost every genre of fiction. But it does something specific in epic fantasy that it cannot do quite as powerfully anywhere else: it gives the stakes a human scale. When the fate of a kingdom is in the balance, the reader needs a reason to care about the kingdom that is not abstract. The found family is that reason. You care about the throne because the people fighting for it are people whose relationships you are invested in.
The Night's Watch works in Martin's story because by the time the larger threat becomes real, you are already emotionally bound to the people standing on that wall. The Black Company works in Glen Cook's series because the found family of mercenaries is more compelling than the political entities they serve. The Kingsmen in the Kingsmen Chronicles work for the same reason: before the conspiracy becomes fully visible, before the magic system's implications become clear, before the full shape of what was done to the kingdom emerges, you are already invested in what happens to Elohl and his brothers.
The specific structure of the Kingsmen Chronicles' found-family element is worth examining. The brotherhood is not assembled in front of the reader — it already exists at the story's opening, forged by training and years of service that happened before the narrative begins. This is the harder approach. Building a found family from scratch gives the author a natural arc: strangers to companions to brothers. Depicting a found family that has already been built, then torn apart, requires the author to make the reader feel the loss of something they did not witness forming.
Carlson makes this work by giving Elohl's grief a specific texture. He is not mourning an abstraction. He is mourning the particular ways specific men moved and spoke and made decisions under pressure — the details of people he trained alongside for a decade, who were removed from his life without explanation. When he finds them one by one across the course of the trilogy, each reunion carries the weight of what was taken and what survived. The reader does not need to have witnessed the original brotherhood to understand what its destruction cost him. The quality of his grief makes it visible.
This is what found family does in epic fantasy at its best: it makes the reader feel the stakes emotionally before the plot makes them intellectually clear. The Kingsmen Chronicles builds its found family in the reader's imagination by demonstrating its absence. By the time the brothers are reassembled — some of them — you have understood what they mean to each other through three books of its cost. That is the work the trope does when it is done right. It converts plot consequences into human ones.