I think you maybe need to rephrase this. There are people on that list like hilariousetc and DdmrDdmr who have given away hundreds of merits, but because they have earned so many they still have lots available to give. You can't really say that people who are on the list of most generous merit givers of all time are also on the list of people who do not give merit.

In addition, merit sources will deplete their source sMerit before their personal sMerit, and so could appear on this list despite giving hundreds of source sMerit.