How to build a relationship between multiple sub-entities and a list attribute?

The model of the (PHP & MySQL based) application I'm currently working on contains a inheritance similar to the one described here. Simplified for the purpose of this question the classes structure can look like this:

To mat this to the database I'm using the Class Table Inheritance design pattern. Here is the physical data model:

The most specific attributes are actually specific for every single subclass. But there are some attributes, that are needed in several classes (but also not in all of them -- otherwise they could be managed in the Foo class/table). When it's a simple attribute, it causes some code duplication, but isn't a big problem. But there are also some cases with complex attributes.

E.g.: FooTypeBaz and FooTypeBuz should contain a list of Whatever elements.

Normally I would implement this 1:n relationship with a table whatever containing FOREIGN KEY. But in this case I would need multiple FOREIGN KEY columns whatever (for foo_type_baz, foo_type_buz, and maybe some tables more). It's dirty.

Another solution: Something like a "facade" table for the table whatever:

Looks better (for me), but I'm still not happy with this model.

How to build a relationship between multiple sub-entities and a collection/list attribute? Is there an elegant solution for this problem? Maybe a best practice / design pattern?