Control placement of specific city states on a random map?

I can see in AssignStartingPlots.lua where the starting plot is assigned to city states by playerIDs. But where is the MinorCivilizations type/id (e.g., MINOR_CIV_WARSAW) assigned to a specific playerID (or starting plot)?

I need to control this in my mod. Not for a WB map. What I need is some Lua logic to place CSs of certain MinorCivTrait in certain places in a random map. Surely there is a way... (Lua method preferred, even if it is a kludge.)