Star, planet, habitable planet, and extreme planet affect each other in sequence order but planet, habitable planet, and extreme planet compliment each other.
More star mean more chance that you will have more planet in total. More planet mean you will encounter a star system that has planets instead of just lone star with nothing, and having more of them. However, these planets are Dead Planet (Class 0) which will be upgrade to habitable planet dictated by the setting itself. Then how many of those will turn into extreme planet is also depend on it's own setting.
Thanks, that's what I was thinking - Planets are set and then it is decided if they are habitable or not.
I like to play with Rare star then abundant of all planet settings. It made more sense that way.
Interesting: I prefer common stars and rare habitable planets because that's how things really are, we have lots of stars but few habitable planets. Although the dead systems do get in the way. (Speaking of which, when do we get terraforming in this game?)