Hi Sub
The architecture of SAP for master data, organization structure (HR structure) has ECC system as a central component.
Hence, also as a part of SAP best practise, initial/delta download of master data, replication of HR Org. structure is done from ECC to CRM. Once you download the organization structure to CRM, you can work on the that organization structure in CRM as a standalone basis.
However, the above functionality is not suited for CRM to SRM organization structure. I am sure, it will work effectively, if you download the org. structure from ECC to SRM.
You may have to involve SAP for the possible solution if you want to replicate the org. structure from CRM to SRM.
Hope this will help.
Thanks and Regards
DJ