Lunatic Fringe

They are mad! MAD, I TELL YOU!!

Okay, what you really need to know is that various explorers found each other while poking their noses places noses don't normally go, and certainly not outside of large, heavily armed groups. Some took to each other and started hanging out. They even built a clubhouse to hang out with each other. They even visit it some times.

It's the most unofficial sort of guild. Why, they haven't even picked official colors or anything.