I'm glad you and others like my map.
To answer your question: When you go to the scenario editor in the worldbuilder you can add and remove the civilizations which you want to be in the map. After that you can edit the starting position circles in the map and they will have the added option of selecting a start for a specific civilization instead of just "random civ" and "random city state".
I'm not sure what you mean with "Strangely no CS appears in the according list in the CS tab in the Scenario Editor." I didn't actually make a custom scenario as in Kalimdor VS Eastern Kingdoms or something, I just added the civilizations and gave them their starting spots.
To answer your question: When you go to the scenario editor in the worldbuilder you can add and remove the civilizations which you want to be in the map. After that you can edit the starting position circles in the map and they will have the added option of selecting a start for a specific civilization instead of just "random civ" and "random city state".
I'm not sure what you mean with "Strangely no CS appears in the according list in the CS tab in the Scenario Editor." I didn't actually make a custom scenario as in Kalimdor VS Eastern Kingdoms or something, I just added the civilizations and gave them their starting spots.