The Pilot flying that lesser amount of hoops aircraft (RAAus Registered) as you say has more training to do than the Pilot Certificate holder. I am not saying PPL should be able to fly the RAAus aircraft although in saying that, in NZ, a PPL or higher licence holder can fly a class 1/2 microlight once he/she has done the conversion. There is no requirement to be a member of one of the two associations that train and issue Pilot Certificates to fly those same aircraft.