In Episode 15 of Frieren: Beyond Journey's End, Stark is hired by a nobleman to impersonate his deceased son, in order to keep up morale during some unspecified conflict.
The nobleman bears an uncanny resemblance to Stark's father - he even has the same scar over his right eye - and the deceased son bears an uncanny resemblance to Stark's brother. The nobleman's other son is seen training alone, in an obvious parallel to Stark's own experiences as a child. It's even mentioned that the nobleman originally hails from the same warrior village as Stark. It seems obvious to me that they really are his long-lost father and brother, and I spent the whole episode waiting for that to be revealed... and it wasn't.
What's the deal with them, then? Were they actually Stark's family, or is it just an insane coincidence? And if it is just a coincidence, is this solely to play up the parallel between Stark and the nobleman's youngest son?