Your logic is completely skewed there. Because Federer has better results than Nadal overall, you are assuming hes the better player. Not so.
Your arguments are easy to pick apart because I use your words against you. You don't get anywhere trying to put your words in my mouth. You won't be able to find this because I didn't say it. So extrapolating upon something I didn't say is nonsense. But that's par for the course.
Sampras, on the other hand, dominated Agassi on US hard courts whereas Agassi dominated Sampras on AO hard courts (different surfaces btw). While Sampras dominated Agassi on grass, Agassi dominated Sampras on clay.
Why did you think this point escaped me? You don't know clay and rebound ace are "the" slower surfaces? I took it for granted that you knew that. My mistake for giving you the benefit of the doubt.
While Sampras dominated Agassi on grass, Agassi dominated Sampras on clay. Pretty even steven there unlike the other one; therefore, the former presents far more interest.
First, you merely paraphrased but overstated exactly what I stated: Agassi > on slow surfaces, Sampras > on fast surfaces. Further, you measure domination by 1 match at RG (QF) and 2 at W, one of which ended 62, 62, 36, 36, 64 (QF).
But more importantly, 90s offered much more variety in terms of surfaces so the challenges were also different and more intriguing not to mention, all these different surfaces provided a much more complicated rivalry.
Not so. It should be obvious that the differences did quite the opposite: Sampras's advantages were greater on faster surfaces and vice versa. Uniform surfaces promote uniformity across majors: Fedal/Big 4, RG being the exception only because Rafa is the GOAT. But for Rafa, Roger has cleaned everyone's clocks. Rafa's supremecy distorts Federer's prowess on clay. But Rafa beat Fed in the finals of AO (4x winner) and Wimbledon (7x winner). Agassi never beat Sampras at USO (5x winner) or Wimbledon (7x winner).
As to the full blown rivalry, Sampras vs Agassi rivalry is already in the past. We saw its start, middle and the end. And Federer vs Nadal are near the end as well. Perhaps another couple of years at best or so but the fate is already written all over the wall.
Then "full blown" isn't your main criteria, rather it's of lesser importance though you stated above it was of "main" importance: "mainly because, they are both fully blown rivalries."
McEnroe et. al., Navratilova-Evert are, by definition, definitely full blown. OK, so the freshness of the rivalry is the most important factor to you. Now I understand why you discount the others.
I hope this helps you understand why your agruments amount to a bowl of word salad.