So, if you want evenly spaced and equal start sites for 7 factions, here's the advice:
1. Use a predefined map, such as Ultimate Builder Map or Map of Planet or some of the others in Apolyton archive, such as Large Realistic Map.
2. Use as large a map as you can tolerate; Huge is best.
3. Set cloud cover to dense, and erosion to strong or average (too many rocky squres reduces resource count). Set ocean coverage to average or lower, unless you are on a huge map.