Random map modding / Historical battles question

Hello, I would like to create a random map when you are able to restrict the civilizations that can be played, where I can see the files from Historical Battles or how I can do it? (Edit: I found where the HB are located, but I don’t know how to restrict the civs)

The second part would be enforcing starting on the 4 Age and disabling the 5 Age, but not the revolution. I bet that can be done easily with triggers?