Oddly, I'm pretty heavily reminded of Eric from Drew Hayes' Spells, Swords, & Stealth series: his late father was a renowned paladin, so he had really big shoes to fill and everyone expected great things from him. Only, he never quite managed.
He was a guard for the town mayor's manor, particularly the mayor's daughter. Except the daughter was regularly kidnapped by goblins, making him appear completely inept.
Then the story starts and he gets captured by goblins; in his effort to escape, he learns the reason he's an absolutely shit guard is because he's actually a fantastic rogue.