GypsyComet
SOC-14 1K
And even so, I guess most Imperial people will be more evolutioned from Vilani tan from Solomani, as the Vilani had already a quite more large population base, having been in the stars for about 2000 years when the Terrans began its move.
The Vilani had been in space for over 7000 years by the time the Terrans developed Jump Drive, practicing social and genetic Darwinism over both their two early competitors (the Geonee and Suerrat) and subsequently discovered Minor Races for at least half of that time. Race Politics have run rampant throughout the setting's history.
The farthest travelling Terran ethnicities documented are the Turks, who were behind the Scorpion Company that poured Terran population into the coreward reaches of the Rule of Man (what is now Julian space) and were a significant part of the Terran contact with the pre-spaceflight Darrians. The Sword Worlds with their Scandinavian origins are next. Diaspora Sector is supposed to be loaded with single-source colonies planted during the Nth IW, and the Chinese apparently "own" a large chunk of Solomani space spinward of Terra.
Many of the other Terran ethnicities that went to space during the Interstellar Wars and the Rule of Man would have just vanished into the melting pot of the Vilani population base. It's what the Vilani do, and they have had three thousand years to do it to the Terran Diaspora.
Terra itself will still be diverse, despite likely efforts by the budding Solomani movement to use certain groups for colonization.