Unless Estonian has been reclassified as a hybrid Balto-Germanic (Scandanavian)—I don’t know.
I had friends who were exchange students to Eastern Europe...One went to Estonia, one to Lithuania, and I went to Poland...the three languages are totally different from each other...
Lithuanian is as you say, related to Sanskrit (there’s even a hint of Latin). Polish is a Slavic language (also a few Latin roots). Estonian is not a Scandanavian language but then again neither is Finnish...Finnish is actually very different from any other language in Europe and Estonian is sort of a sublanguage of it...
Hope that clears things up...