Those who managed to secure a slot in the vanguard fleet are all families with their own fleets. Although the Count Orlan's Family didn't have a fleet, his capable son-in-law did.
When renting the fleet, Count Orlan even had an in-depth discussion with Hudson.
In the end, the two reached a unanimous conclusion: the best way to eliminate the threat from the Clergy's followers was to pack everything—people and goods—and load them onto ships.
For years, the Clergy had been implementing indoctrination education in their stronghold, turning the low-level serfs into blind adherents, their thoughts and actions entirely under the control of church clergymen.
As long as those clergymen are replaced with Kingdom clergy, these serfs would become the most obedient subjects.
The Alpha Kingdom is desperately short of people, and it wouldn't matter how many were brought over.