You wrote:

" Your whole point is about what happens if the function is not use the user's default schema. So your reply that it uses the default schema is...

First....

You don't need a table for each view.  I have one set of tables all owned by 'dbo'.  I can have multiple views on these tables all owned by different...

I disagree.

That is why MS implemented default schemas.  If I have to (or should) specify the schema in all queries, I get zero code reuse.  By using the default schema,...

The reason you are having trouble with the query is because of the table design.  I recommend you create three tables.  One for Pupil, one for Service and a M:M...