the Estonian longship issue has to do with the entire Baltic coast not being flagged as ‘northern Europe’. I still went Estonian in one of my Rurik playthroughs. And then intentionally disintegrated gardariki seized litomeric, swore fealty to Bohemia then seized the throne after going feudal. Those 5 stacks of cultural archers worked great for that.
What do you mean? Going by the geographical terms, Finland is "Baltic" as it means countries on the eastern shore of the Baltic sea and it is in the correct geographical region.
The thing is, e_Scandinavia = geographical Northern-Europe in CK III and k_Estonia is in e_Scandinavia.
The Balts should not have access to longships as that would be a bit ahistorical. The Livonians were seafarers and raiders just like the Estonians but the Livonians were a Finnic people very closely related to the Estonians of Saaremaa.
The Curonians (Baltic tribe) started raiding over the sea after they had assimilated/integrated the Livonians they conquered in the 12th and 13th centuries. Seafaring terms/words in Curonian and Latvian mostly have a Finnic origin because seafaring was a foreign concept to the Balts before coming in contact with the Finnic people inhabiting all coastal areas.
So this is comparable to a culture conquering its way into the geographical region of Northern-Europe and then getting access to longships.