Addendum: Penner on Grote and Sachs

I note a recent paper by Terry Penner, which I've just discovered, "Platonic Justice and What We Mean by Justice", where in footnote 38 (page 67) he refers to Grote but claims that Sachs offers a distinctively new criticism. (Not that this would help with my worry: even if the criticism is in some important way new, of which I'm unsure, still, shouldn't the argument that the criticism is new, relative to Grote, have been made before it was published? And presumably in the process many of the points which Penner wishes to make would have been clarified.)