Need guidance in setting up Franchise and Distributors on the same instance

I want to setup Franchise whose users will log in to the system and use POS.

In the same system want to give access to Distributors so that they can create sales orders and invoices and also manage their sales persons.

Here Items will be common between both. And Distributors should not be able to see each other’s customers and other Sales related data.

The reason why I want items to be common between both is because there are 6k items and we want to control various pricing of items centrally.

I am confused as to how I should setup this up.

Should I create each Franchise as a sub company or as Customers?

As for Distributors should they be defined as Sales persons or they should they be also defined as sub company?

Any suggestions will be helpful to for getting started.