There are a limited number of places where it makes sense to build a city. Places close to water, for drinking and transport. Flat places, near agricultural land, not too far from existing cities, nor too close to better sites.

Likewise, a city, being established, will generate demand for certain services. Farming is a necessity, as is transport, and eventually manufacturing. But all these things depend on, and are made possible by, accounting.

Specialization means that it is efficient to have a centralized clearinghouse for people to settle accounts, staffed by people who are fast at arithmetic and known for being trustworthy and meticulous. And in a place of employment like that, there are only so many ways to arrange for customers to easily make their way through the building with the minimum of fuss.

So it is not, ultimately, all that odd that two different Earths happened to have banks with nearly identical floorplans built in the same spot. It is a coincidence that a roving microportal happened to pass exactly over three masked figures just as they attempted to rob it.