Question: Is it possible to make updates to multiple workbooks at once if they have the same fields/dashboards? Do I need to merge all data from the start and create one giant workbook with dashboards for each client within it? Are there other options I'm not considering?
Yes. You can change the backend data connection and have it 'update' all of the vizzes that are connected to it without needing to change the workbook.
No, you don't need to merge all of the data from the start, but its a consideration you should probably seriously think about when applying the customer id filter due to the increased risk of complication when you split this down into multiple workbooks. You can handle the different logos by using the same filter that you use to restrict the data and a layout container. My preference would be to handle it inside a single workbook for this reason alone.
If you have your server setup correctly, you could configure it to ensure that the data is kept in a single repository and updated independently when the vizzes load (live connection). If you go down the other path and generate extracts for each client workbook, then you will have to update each one as each extract will be stored separately on tableau server.
Thank you for your response! Let me clarify a bit.
Question: Is it possible to make updates to multiple workbooks at once? Each workbook has a different data source, but within that data source are identical field names. I am more looking to understand if I can add calculated fields or new dashboards to all of my workbooks at once.
Clarifying: "You can handle the different logos by using the same filter that you use to restrict the data and a layout container.". Can you explain this a bit further?