"Random" vs. "Fixed"

Does anyone know which files are responsible for generating random maps? Not just the template itself, but also its content. If it's not too much trouble, could you please share them? Or does anyone know how to balance a random map based on the content described above? In particular, I'm interested in key objects such as: utopias, conservatories, hives, and dwellings. Is it possible to specify somewhere that they should be generated "equally" between both players? Thank you in advance!