An obvious mistake on a map. There is no such "language" - Latvian. Latvian is a modern mix of Latgalian and German, less than 700 yrs old (some say Kuronian also was there). Semigallian is a hoax. Bishop Albert in "Chronicles" called tribal cultures "Semigalls" - half galls! They probably spoke balto-slavic proto-language, closer to some proto-Russian, than modern Latgalian. Their rulers were actually russian counts, mentioned by the same Albert in XIII cent.
So the actual branch is Kuronian, Latgalian, Galindan, Prussian. Not sure about Selonian. Sudovian - recent Polish invention, never existed. (suudi in Latvian means sh#t). Add modern chimeroid langs as Lithuanian and Latvian and pic is complete. I suspect Indian branch has the same problems.
Edit: forgot vod people, also called krevingi, they still existed in the end of the 19th cent, few families.