I understand that Serbian family names used to come from the father's name plus the addition of some characters, e.g. the son of Marko became Markovic (apologies, I cannot put the accent on the c).

I wonder, though, as family names have become fixed, if the names above could be related, or if they are different families?

I copied and pasted the Cyrillic due to not having a Cyrillic keyboard and not reading Cyrillic yet.