There are surnames that sound more Bosnian ,Croatian or Serbian, it's simple curiosity as I can't get the information either from wikipedia or the account of that match at 23andme.
Broadly yes ,Balkan people are close to each other ,nonetheless, if we look closer " genetically indistinguishable" I will not agree, there are still slight differences, either autosomally or by distribution in Y DNA. On a pca plot, like for exemple those from Aleksandar Nevski, or those from Doug Mcdonald or using calculators at Gedmatch or whatever scientific publication about population genetics, Croats tend to cluster more with Hungarians or Czech while Serbians tend to cluster more with Romanians or Bulgarians. Same on 23andme ancestry composition, Croatians tend to get higher percentage of "eastern_european" admixture component which is built from Hungarians, Russians, Polish, Ukrainians DNA samples. But again this is slight and it does not makes me feel sad or happy about that, it's just an observation.
On the other hand I have plenty matches from ex-yougoslavian countries, whatever they self-identify nowadays either by nationality or by religion I have one common ancestor with them. This is the norm for everybody from balkan, I agree on that.