Separating them might look counterproductive but these races other than the elves and the dwarves rarely meet each other.
If Katarina and him force these races to integrate with each other, it might backfire. It is better to let them mingle naturally.
Of course, if Azief and Katarina is planning to stay here long, some other methods could be taken.
But since they are not, some forceful method better not be executed in fear that it would lead to instability.
There are also the slaves that is already the inhabitants of the main world and had deep understanding of the more mystical stuff.
These people are the human descendants of the slave that was taken from the slave world in the past.
Unlike the humans and elves that just newly arrived in the main world, these slave descendant, elves and human alike have great relationship with each other.
They even intermarriage with each other, creating half-elves children.
