>>2956547I1/I2 Germans are descended from a SHG shifted ANF population mixing directly with Estonian/Danish CWC that entered scandinavia from the South and the East. They were the progenitors of the Boat-Axe/Battle Axe & Dagger culture and carried a certain R1a variant to scandinavia.
<Balts are a different story however, and are a Baltic_HG population that mixed with a late stage corded ware + cucetini population.