Why there are two Serbian languages in Musescore app translation?

There are Serbian (Serbia) with approx. 60% of strings translated, and Serbian (without country) with approx. 30% of strings translated. I'm not from Serbia, but I far as I can understand, the Serbian language has no country differences, because the nearby countries have their own languages Montenegrin, Bosnian, Croatian... (before it was called Serbo-Croatian, but now every country have a denomination for the almost same language). Maybe will be better to mix the two translations and create a unified Serbian translation with more strings translated. Again, I'm not Serbian so maybe there is a reason to be separated, but that is my idea.