Ribbon Workbench ... always on "Add Existing" entity

I'm just digging into the Ribbon Workbench.  I'm reading through the fantastic help information found here: https://ribbonworkbench.uservoice.com/knowledgebase/articles/71374-1-getting-started-with-the-ribbon-workbench.

I have a "Social Service Solution" which has customizations to the Case entity.  To make customizations to it's Ribbon, should I create a new solution on top of it and add just the Case entity so its changes are separated from the Solution Service solution?

I'm not fully understanding what separating them would do.