Hey, /vp/, how does gym form? How leader get pragnent?

Seriously though, do you think the gym type is decided by the new leader or the pokemon league? Is it based on the types of the surrounding areas? How does one replace a gym leader, do you think its a group vote, or does he/she name a successor? What about when a leader suddenly dies?

Let's use Surge as an example. What if someone wants to oust him and take over his gym. How do you think they'd accomplish that? Would they then have to be electric themed or could they pick a new one? Would the new type be decided by the League? SO MANY QUESTIONS.

Yeah, I know, it's stupid, fuck you, I'm curious.