Need a last name system that's not...last names

Okay, so I'm fleshing out this pre-existing culture, (The Argenta from Doom) for a TTRPG I'm making for my family to play, and I'm a bit hung up on how their last names should work.
What I don't want, is a system like ours, with family names. That doesn't fit the culture very well. However, what I need is some system of people being able to tell each other apart even if they have the same names.

For example, we'll use the character Valen, because I love him because he's who I'm working with right now. My options I've thought up so far are:

• Valen Night Sentinel (occupation name)
• Valen King's Hand (position name, given/earned)
• Valen, Commander (Rank)
• Commander Valen, and leave it at that.
• A given/earned name based off a trait or achievement, so when confused, one could say
  "You know, Valen."
  "Valen…which one? I know three."
  "Ahhh, yeah. You know, Trustworthy."
  "Ooooh, yeah, I get ya. What about him?"
  etc.
• That last option, except keep the word in the Argenta language, so it would be more like
  "Valen? Which one?"
  "You know, Nakoth."
  "Ahhhh, yeah."

I'm more than open to suggestions, because currently I'm not a huge stan of any of these. Thankie!!

In my world a son's last name is his mom's first name with 'son' on the end. Say.. Mike Anna-son. And a daughter's last name is her dad'd first name with 'daughter' So, Abby Sam-daughter. Sometimes it sounds weird.

Ooh! That would actually make decent sense for this culture tbh…Thanks, I'll be playing around with that idea!

in case you're still looking for options, there's always the locative option! at least in European culture, surnames developed partially as people grew more mobile and started distinguishing each other based on where they were born, landmarks they lived near, or where they worked. so you could have Valen Underhill, Valen Atwood, Valen Millbrook etc., and the assumption is that people would know "oh he's the Valen that lives under the hill, not the one that lives in the woods".

Hmm, that is an interesting idea! (And yes, I'm still in the market for ideas xD)
I do like that, but it drifts into last name territory a little too much unfortunately. Since these guys are already so similar to humans, I need every detail I can to help remind my players they're not human, or on an earth culture

I use both places and parents names for one of my culture. They are not Anna Tanguay, for exemple but Anne of Paris daughter of Charlotte. Other family names can derives from dynasty, from lords and ladies who own that person. The wikipedia page on surnames is actually quite interesting https://en.wikipedia.org/wiki/Surname#Acquired_and_ornamental_surnames