You are cherry picking to support a losing argument. The 2.5% better in 2016 is an irrelevant number. First it says nothing about 2012-2015. Second, if Clemson gets 1 recruit with a 98 rating and Miami gets 2 recruits with a 96 rating, they are 2% "better." I'd rather have the two 96s. And you honestly think that 2.5% better recruiting is the difference between winning a national championship and going 8-5? If you believe that, then it would appear that you dont understand player evaluation. The only thing the Texas Tech number shows is that they are also bad at player eval and development. Players slide up and down the ESPN top 300 rankings all the time. A guy leaning Clemson might be ranked 60th, our guy is 55th. Then Al Bundy Jr scores 4 TDs in a game and commits to Clemson and suddenly he is ranked 30th. It doesnt mean he is that much better.
Because the evals are subjective and players bounce around the top 300 based on where they commit and game to game performance, the better metric of a good class is the raw number of top 300 players. Clemson might get 10 recruits ranked 190-200 in the ESPN rankings, Miami might get 10 ranked 220-230. No person who understands recruiting would say Clemson blew Miami away because all their top 300 are higher. Its basically a wash due to variability. Fact is that from 2012-2016 Miami and Clemson had the exact same number of top 300 recruits. Our best season was 9-4. They made the playoffs multiple times and won a championship.
Also, are you claiming Clemson had the 4th most 5 stars when they played in the national championship game in 2014? They were in a four way tied for 8th overall (according to 24/7 they had 4 5 stars, 29 4 stars, and 37 3 stars). Miami was not far behind in a 5 way tie for 10th overall (2 5 stars, 24 4 stars, 45 3 stars). The small variation does not explain the discrepancy between a 9 win season and playing in the national championship- especially when you see the positions their 5 stars played (Watson was not a 4 star).
Of course Clemson separated themselves now and 5 stars are knocking on their door- winning multiple championships tends to do that. What I'm interested in is how Clemson got to where they are. When they won in 2015, they had the same number of top 300 players as Miami. That is a fact.