The ranking isn't relevant, unless we separate merit-sources (including ex. merit-sources) and non merit-source. The generosity score depends on how much merit allocation for each merit-sources and whether they spend all of them or not.
This could be an idea.
Generosity for a non Merit source is relevant, as a way to signal how many of their hardly gained sMertis are actually distibuted. So I think we could try to do a seprarate ranking for them.
A per MS something similar could also be made, but it would require each one of them to reveal their smerits allocation, something not everyone is willing to do (with valid reasons, of course).
So I think a generosity-ranking for no merit soures has a good added value.
That also could be something relevant to mention when requesting to be considered to be a Merit Source.