The argument that Nadal is the least impressive off clay is completely irrelevant. Clay is not only equal to grass or hardcourt, it is in fact the dominant surface outside the States for hobby players, and it is the toughest surface physically and mentally. His slam tally minus clay is 6, which is as much as clay-hating Edberg or Becker won altogether. Rafa is not as good on hard and grass as RF/Novak but he isn't inferior to them on it, he's beaten them in slam finales on those surfaces (except Novak on grass, we don't count 2007), yet Nadal is SUPERIOR to the two on clay, in a way in which neither of them are superior to Rafa on hard or grass.
People like to say "but if we take away the 11 FO ttrophies"... That is ridiculous. These are slams as valid as any. If not more so. i don't subscribe to English hype that Wimbledon is THE event. That is propaganda. It is hogwash.
Regarding longevity, it is subjective whether longevity should be the primary factor. It is simply one of the many factors. RF's fans tend to cherry-pick what suits them, and I find that a sign of desperation. If they were so confident in RF's GOATness, they wouldn't need to resort to such strange claims as "clay is inferior" or "longevity is key" or "but Federer plays the aesthetically best tennis". The thread OP very clearly explained why the trio is pretty much equal when everything is summed up. A case could be made for all three being GOAT - if there was such a thing as GOAT, which I doubt - hence none of them are GOAT. They are a remarkable trio, and it is TOGETHER that they made each other great.