Hi John!
One thing about the 6 hours a year for the NPPL, is that it is no less over 2 years than a 'normal' PPL. Since you need to do 12.
So there is really no saving if you are only going to fly the absolute minimum hours, and let's face it, if you are only flying the bare minimum, you are hardly going to be a complete genius in the air anyway!
The more you fly, generally the better and safer you become.