I tried to use only UN approved names. « Somaliland » isn't on unterm.un.org, it's why there is two Somalia. I'm pretty sure that Eritrea isn't on the map because of a display bug.
Definitively, if you are making a map, your have to make geopolitical chooses. And yes, I have edited NE data to highlight the geopolitical choices that I think are the simplest to defend.
The western one should be Somaliland, as you mention. The map seems to take the duck-typing approach to countries, rather than taking the official stance of any one country. There's Somaliland, Taiwan, Kosovo, Cyprus, Israel and Palestine, etc. No Northern Cyprus though.