Partner schemas in appropriation requests

Hi All,

Following is the Approver set up needed for AR in our process:

PC                        Amt                               Approver1                 Approver2                      Approver3                       Approver4

Profit Center 1     amt<100k $                           A                               B

                          amt>100k $                           A                               B                                 C

Profit Center 2    amt<100k $                            D                               E                                 F

                         amt>100k $                            D                               E                                 F                                  C                             

So here based on the Profit Center maintained in the appropriation request the approver changes.

Here my first question:

Business want to place a validation on the Approvers that is if they wrongly maintain an approver which is not mapped with the Profit center then an error message will be thrown. Is it doable in standard? My idea is to maintain a Z table with Profit Centers and Approvers mapped. And build a custom validation for this.

Second:

Should I maintain three different partner schema with all approvers as mandatory? And assign this to three different Appropriation Request type?

Or we can maintain only one AR type mapped to one Partner Schema with two approvers as mandatory (the minimum approvers is 2 as above) and then manually add the others as required in the Partner Overview in the General data of the AR. What would be best to follow?

Regards,

Suman Misra