[I am not an approver]
I would try to judge art on its own merits instead of counting how much a given artist has active; "approvability" of art can vary widely within one artist's body of work.
However, I'd note that only two of that artist's posts were actually approved (search: "approver:any"). Not to say that the others wouldn't be, but they probably shouldn't be used as a heuristic.
