How to autogenerate item sequence number based on item category selection

Summary:

The Item rules are working as expected - But the Problem is we have more than 12K plus categories based on UNSPSC code.

Does it signify that we have to write 12k plus rules to generate the Item Number based on the UNSPSC that we have defined.

Content (please ensure you mask any confidential information):

Rules Screenshot -

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):