Think of the capacitor as a barrel with a hole in the bottom, a small hole. The barrel gets filled by the number of pips and the capacity of the barrel is the class and grade of distributor you have. Now, perversely, all barrels regardless of how big they are, have the same size hole in the bottom! You can pip in as much water as you like but it can only run out the bottom at the same rate. This is why small shields get 'filled' or charged faster than large ones.
So really all you need is for that flow out the bottom to be there, the barrel need not be full or continuously being topped off by full pips. An inch in the bottom is as good as a full barrel. Pips are almost irrelevant.