The article makes some great points.
And, I can agree that Nadal's 13--7 H2H can be a bit "misleading."
But, I don't agreee with the fact because Nadal has a far superior clay H2H as compared to other surfaces, and because he has not returned the favor of meeting Fed in more non-clay tourneys, that the H2H is somehow totally negated, as some on these boards posit.
The idea that a H2H is completely non-legit because Nadal and Fed have often met on Nadal's best surface and Nadal has not reached enough finals with Fed on other surfaces to improve Fed's record in the H2H, is baffling.
It's basically saying that no H2H's between any players are completely legit unless there are an equal number of matches under conditions that suit each player the best. The likelihood of that happening are minimal.
At some level, a match is just a match. Fed had many opportunities to improve his clay record against Nadal. He was "in" most of the clay matches he lost to Nadal. The H2H didn't have to be that bad for Fed, even without additional hard court, indoor, or grass court matches
Don't get me wrong. I fully understand the surface analysis and believe it has some merit. But, the idea that it completely negates what Nadal has accomplished H2H with Fed is ridiculous.
And, in the end, all the dominant H2H against Fed says is that Nadal was a great player who matched up well with Fed. It doesn't make Nadal "better" in the context of their entire career acheivement, and it doesn't suddenly make Nadal (with only 6 Slams to date) the GOAT, or (so far) even a legit GOAT candidate.