Questions about Deparments and Accounts (patterns) for Azure Enrollments

Hi guys,

while thinking about which "Department/Account" Setup methodology is the best for our organization, there appear some questions from my site.

As you know, there are three common patterns for Azure Enrollments (https://docs.microsoft.com/en-us/azure/architecture/cloud-adoption/appendix/azure-scaffold#departments-and-accounts).
In additional to these 3 options (functional, business unit, geographic) there is one more way like this:
Enterprise -> Accounts -> Subscriptions

This is an away, without creating a Department before.

My questions are:

Questions to deparment:

• What are the advantage of building a pattern with Deparments?
  I mean, why should I create it Departments, when a direct connections between (Enterprise and Accounts) is possible?
• What disatvantage has a pattern like Enterprise -> Accounts -> Subscriptions (without deparments)?
• Due to the reason, that deparments are not deletable (only set to inactive) and one department name, which was in use, isn't usable anymore for new active deparment I tought that we could set the Name of the deparment like this: "Department 1", "Department 2", "Department 3" etc.
  
  The knowledge which department is which deparment in our organization we would do this information in two place: 1) in cost center of the deparment 2) in our internal documentation.
  
  Question here:
  Is there any reason or any restriction to information, if we would do it described above?

Questions to Subscription:

• Is in a EA offer possible, to move one or more Subscription from one Deparment A to department B ?  If yes, with or without downtime?

Questions to Accounts:

• Is it possible to assign mutiple Account to one Department?
• Is it possible to move one Account assigned to Department A to Department B with all their Subscriptions? If yes, with or without downtime?

Please let me know if you need some more informations.

Thank you for your reply in advance.