Org hierarchy with divisions & Dept modeling


In our organization, the way we have org chart as below. we have two Units that focus on manufacturing operations (Cogs) - BU_1 & BU_2. These business units share about 3 departments - product development, manufacturing, sales& marketing - dept_prod, dept_manufacturing, dept_sales. We have another department in our Corporate office - dept_corp to which Balance sheet, income and tax accounts are going to be linked from COA perspective.

I was looking through Technet best practice while setting up Org hierarchy and it is interesting to note the BU & Department -

"Create a department to model the intersection between a legal entity and a business unit. You can then roll up data from a department to a legal entity for statutory reporting, and from a department to a business unit for internal reporting.
Departments can serve as profit centers. If you use departments, you do not have to use both legal entities and business units as dimensions in the account structure*. You can use just departments as a dimension. However, you must use both cost centers and departments as dimensions in the account structure if cost centers are used only as cost accumulators, and departments are used for revenue recognition."*
If we were to set up a hierarchy Legal —> BU → Department, we may not be able to model it because all 3 departments need to be linked to both the Business Units (which AX doesn’t allow). However, I can use the “BU - Department” dimension in the account structure so I can report on BU-Dept;
we want to see the financial statements by BU, Dept, Customer and Product line.
Question is: 1) do we need to include Customer and Product lines as dimensions in the account structure?
2) Org hierarchy perspective- how could we connect from legal to BU to Departments? Could we just go by Department. Ie. Legal and all departments? what are the implications from reporting stand point as well as user access and security?
Thank you

Hi all, I am curious to know of your feedback and how you would handle this. Thank you