No doubt. But why does it have to mean that they have the right for duchy’s history while Belarus doesn’t? Why do they have Vilno then? There’s no proof that Samogitians founded the duchy, but Vilno was in Belarus in the Russian Empire, not in Samogitia.

Balts may have claims against our land suggesting Belarusians assimilated many Balts. Belarus is fully encompassed with Baltic toponyms, hydronyms and austronyms

When you say “Baltic” which ethnicity do you mean? The Baltic Sea is quite big, so this word could even include Swedes, no?