B73, I agree in theory you don't need the credits for the MPH type (caused me a bit of puzzlement when I saw that!) but I guess from a practical viewpoint you don't want to be getting stuck into the books after a couple of years, to sit the ATPL exams, for the licence itself once you have the hours.
Edited to add, Dump the Pole, you will need the MCC for your first MPH type, regardless of licence or whether you are a captain or not.