There was more "depth" on clay when there wasn't someone as good as Nadal so the not so great clay court players could win Roland Garros and make the final or semifinal: Kafelnikov, Gaudio, Moya, Medvedev, Magnus Norman, Filip Dewulf, Stich, Henman, Korda, etc.
If these guys from the 90's are tougher competition on clay than a prime Federer and a prime Djokovic I've heard it all.
Kafelnikov made Moya look like a chump on clay at the end of his career. He was a VERY formidable clay court player at his best. I would say, however, that he was a matchup type guy. Didn't have the fortitude to find a way to win in style matchups that weren't favorable to him, and even in a decent style matchup he would get out-hearted by Kuerten.
Stich was a wild card type guy. You really should be surprised to see him lose or beat anyone in the world on ANY surface on any given day. Same with Korda. I mean Tsonaga is kind of like that. Some guys have electric, overwhelming talent/ability when "on", but struggle to put it all together.
The tournament also played "just like a hard court" in 96 due to it being unusually sun-baked. There were a lot of anomolies that year with pretty much all fast-court players in the final four.
Henman was a surprise sure, but not THAT surprising imo. Every now and then a serve and volleyer gets hot on clay and plays like they have nothing to lose, and gives baseliners putting too much pressure on themselves fits. That's what happened with both Rafter and Henman. It happens. It's a myth that serve and volley can't be effective on clay. If a serve and volleyer gets hot, and is volleying well and is able to wrong his opponents at the baseline on his volleys, they can be very effective. Just ask Edberg. Martin worked Berasategui in the finals of Barcelona...is he a clay courter too? No, of course not, but like I said, the best way for a volleyer to play on clay is to stick to their guns and make the unprepared and unsettled clay courter pay.
Norman struck me as a Kafelnikov type clay game, rock solid, but with more perserverance and heart.
DeWulf is one of the all-time mysteries. Don't ask why, even then he was like a what the heck is he doing here feeling? That too happens sometimes.
Medvedev was an AWESOME clay courter at his best. He had some of the most penetrating two-handed backhands I've ever seen. Medvedev could give anyone a run for their money on clay. I really don't know why you seem to think so little of him. The guy pasted the ball from the baseline with consistency, and was very intuitive about the right times to mix in net rushes and had a very good, solid volley. Nice court sense and feel around the net. Maybe his head wasn't always in the right frame of mind, but a positive thinking, good attitude Medvedev was no one's favorite draw.
This day in age, the reason why other than Nadal you see the same guys in the semis over and over is because, guys these days are raised with hard courts in mind first and foremost from an early age. Bruguera in his day never played on any hard courts growing up, it was a huge disadvantage once he hit the world tour. The REAL prizes and fruits in tennis are not on clay, they are elsewhere. And with the court surfaces becoming so homogenized, it happens to be that styles of play become more homogenized. And right now, you have a small handful of guys who aren't specialists per say, but the best guys adapted for TODAY'S playing conditions. Greater variety means a greater occurrence of upsets imo.
The reason is not just talent level, but rather because playing a guy with one style today and than a guy with a totally different style in the next round, say how Rafter and Henman did it at Roland Garros, can potentially "throw guys off", they suddenly find themselves feeling like their games just not quite in sync today. If you drive on an open-lane highway going straight forever more, who do you think is going to conssitently win the race? Easy, the cars best adapted to those conditions. In that case, that would mean the fastsest cars that drive best in a straight line.
Now, what happens if you throwing VARIABLES into the mix. Like you have to factor in parts of the race/circuit taking place on dangerously curvy mountain roads, and other parts of the rac/circuit on ice/snowy conditions, and other parts in rainy conditions, and other parts on extended downhills slopes going up and down like in San Francisco, and other parts in chaotic, hectic bumper to bumper city driving, etc., etc.? In that case, the results would become much less predictable. In those kind of worldwide conditions, a far greater variety of indeosyncrasies and styles would develop. Predicting how all these different styles will interact with each other when all thrown into the mix at the same time in each venue would become more unpredictable. More variables = more randomness; it's no long a simple case of saying, ok the three or four best are always going to be the best forever more every tournament, because with so many different styles of play navigating the waters, the potential to get caught off guard, or out of your optimum rhythm, or to get blindsided on any given day goes way up imo.