Territory Management Create/Update via OData Services

Hi Experts,

I am looking for a solution to perform a two operations on a territory hierarchy via 3rd party.

Here is the scenario:

I have a territory hierarchy as mentioned above in C4C system. (Boxes filled in blue  ).

Create Case: 3rd party provides input parameters as Root, A, Z, Emp 1, Acc 1 . I need to check if Territory Z exists anywhere in the Root hierarchy. Since it is not present, Territory Z should created under Territory B with Emp and Account provided as an input by third party.

Cut-paste Case : 3rd party provides input parameters as Root, B, Y, Emp 1, Acc 1 . I need to check if Territory Y exists anywhere in the Root hierarchy. If yes, what is parent node? In this case, parent node is A. Since the input parameter mentions B as a parent node, the service should cut the territory from A and paste it as a child node of B . When we paste the territory, Employees and Accounts should also be pasted.         

I could not find any standard webservice which can suffice both the requirements. Is it possible with  OData Service? The customer do not have SAP CRM On-prem.Is building a custom web service recommended? Which one should be the best approach to achieve this requirement.

Regards,

Preeti