You can ignore regions if you find it confusing but I think the text in the body of the message is straight forward.
Rather than creating 50 different domains and instances of WP, I thought it would easier to have an office’s home page as https://www.mydomain.com/myoffice1 or https://www.mydomain.com/region1..region100 is that appeal to you more.
The problem I run into is the management. How does one give access to only the pages that are associated with their respective region or city.
Thanks.