ERD of your Data Warehouse - Star schema has to be based in something.
I'm definitely missing something (which, of course, is off topic). The data warehouse IS the star schema(s). Other than staging/landing and interim tables, I don't plan to have any relationally-modeled tables that store source system data - that seems like a waste to me. The star schema should be modeled how the business itself understands the data.
Back to being on-topic - I posted the same question on the Kimball Forum, if anyone is interested that group's responses.