That wasn't my greatest reply ever - I was in a rush. Yes, Dawkins included species in your quote. And Williams (1966) defined the term "group" in a way that didn't explicitly rule out species. So, I agree that some prominent folks have included species under the group selection umbrella at least once.

However, at least 90% of group selection models deal with sexual species. If you claim group selection exists, and then exhibit species selection to prove it, an awful lot of evolutionary biologists are going to say: "well, that's just species selection - we already know about that".

Interdemic selection has a problem not found in species selection - namely gene flow typically tends to quickly destroy variation between groups. It is that that effect that Maynard-Smith modelled in the material you cite - and it is interdemic selection which is the most controversial.