[@Darkraven]


To seed a planet. Probably a couple of hundred of people on one large ship, realistically. With some escort ships of some sort out of pragmatism. How they live to their seeding point is many. From generation to simply using uploaded minds.


Earth currently is totally colonized and we barely have enough tech to peek outside our own tiny sol system. The empire assumes two things, one. The native planet is totally ruled by one faction, if so. That planet has a large amount of land and finally their original galaxy have many planets with a lot of land.

Maybe I confused star systems with galaxies. Which, would make sense. But I get what you are saying. 

Finally. Seeding is not a one stop drop. It's much easier to have a set up crew- which would be a smaller force. Then gradually send more people over time in bulks. As only so many populations will move just to seed a new planet-