–TLDR: Don’t place home stars too close together on your custom map.
I have noticed that when setting up custom maps if you place home stars too close together AND start each player off with more than one star the map will kill off some players and give the remaining one many stars, before the game even begins. This happens whether you use a random spread or symmetrical spread, because they are too close together.
The following are 24 player maps that give 6 stars to each player at the beginning. I accidentally bunched them too close together. I was going for this:
Instead I got this:
The third time I tried playing as one of the missing players. The game starts me off on another player’s star with only one ship. I assume that once the game stars I would claim the star, but haven’t tested this.
If you start them with only one star you get this: