Improve CF/DSG 9.2 instance dimension testing

GENERAL COMMENT:

Rereading the CF 9.2 section I have a question:  What does this test even check for?  9.2 simply states some terminology used in a certain case.  There are no Shalls or Wills that can be derived from it.  

If a variable has a first dimension that is an instance dimension, then the variable.shape[0] should always be == len(instance dimension). 

If a variable doesn't have a first dimension that is an instance dimension, then the variable.shape[0] should still always be == len(first dimension). 

I don't get the need for this check at all.