I agree that random locations are appropriate.
When the immigrants become self-sufficient, locations of their choosing are ideal.
When the immigrants are not yet self-sufficient, it seems best to avoid large populations in concentrated areas. ( This brings overwhelmed schools, healthcare systems, and other shared infrastructure, to the disadvantage of both the immigrants and the citizen population.)
Wherever they can afford to like everyone else.
Immigrants are just like us. In fact I was also an immigrant - nobody bussed us anywhere. Just find a place to rent and that’s it.