Cities are too small and unviable to tie an entire organisation to.
There are some newer orgs that primarily focus on 1 country (or language), the likes of karmine corp and Loud.
Which has helped them create a more tight-nit and die hard fan base/culture.
For a lot of the older orgs it didn't make sense to limit themselves to one market due to how small each individual countries esports interest was.
Some of the appeal of esports at the time was the ability to have competition which wasn't bounded by geographical location.
You will see a lot of the older european orgs have spread themselves into the "newer" countries/markets because at the end of the day esports is a business, expansion and capitalising on new opportunities is successful.
Fnc for example have a few teams and content creators in japan.
NIP are on the extreme end with ties to Brazil and China.