Best practice for AME approval to be done by employees across business group

The customer I work for has recently acquired another business and we are in the process of migrating that business's finance processes to Oracle eBS r12.2.4. We have currently decided to set up this new business as a separate business group with its completely standalone organization hierarchy structure. We have got HRMS and all other finance related applications installed for this business group. One requirement for this merger is to allow employees across business groups to approve payables invoices and purchase requisitions using AME.

Can someone tell me if that is a good option to go for? What does Oracle best practice suggest? Would it be better to have both the business under the same business group with different operating units?