Multiple master tables for details

Some of the tables in our systems have multiple master tables, for instance customers, they are a detail to say a mailshot, a detail to a purchase type, a detail to a support contract type etc.
At present I create a view that is a second copy of this and then add that, but I also then have to replicate all of the other tables that have customers as a master and so on to keep the drill down.
It would be extremely useful to be able to have multiple master tables so I could add any number I wanted.
Any chance of adding this in a future release?
Or have I missed a simple trick here?