Yes, that is correct. A bit of a training issue, but that is not unusual.

It would also be possible to use Scope Assignments to "lookup" the measures through the BU dimension, in the case that an end user wants to use the product dimension but look at financial numbers.

This will however not change the back-end design we have just spoken about. I can definitely recommend that you read Chris Webb's blog post on the subject: https://cwebbbi.wordpress.com/2013/05/29/aggregating-the-result-of-an-mdx-calculation-using-scoped-assignments/