Combining Models with common tables

Hi.  i have combined 2 models together in a new model but both models havea  date table and a brand table that are used in each of the models measures in USERELATIONSHIP type functions.

Obviously i'd like to use a single date table and brand table for reporting in the combined model.  The only way i can think of doing this is create a new date table in the combined model and create relationships between DateTable 1/DateTable 2 and the new Datetable.  Similarly for brand.  Is there a better approach than this?

Thanks for any advice

Mike