Can we change the Multi Org Structure during Upgrade from 11..5.9 to R12.1.3

Q1. Can we change the Multi Org Structure during Upgrade from 11..5.9 to R12.1.3 for below scenario?

Q2. Is Re-implementation in R12.1.3 is the only way to change the Multiorg structure for the below scenario? 

Scenario given below

 We are on 11.5.9 and we are moving to R12.1.3. Currently our Org structure in 11.5.9 is. Each OU is attached to its LE.

Current Multi Org Structure

Business Group--> Set of Books 1 ---> LE A --> OU A

                                                           ----> LE B --> OU B

                                                           ----> LE C --> OU C

                                                           ----> LE D --> OU D

Currently there are no issues with this Operating Unit Structure, Since all Operating Units are different service centers dealing with customers and invoices. Business do want the Data segregation among the OUs. The Tax reporting is done by a single entity. As we are upgrading to R12.1.3; It has been advised that we should change the Organization structure to