No, GSP is the more skilled fighter, not the better fighter. If Superman showed up this moment with zero MMA skills, he'll be the undisputed best fighter in the world with his strength and speed alone, via being able to beat everyone else in a fight. Skill is just one aspect of fighting, it's important, but so are strength and size and mental fortitude and stamina and fight IQ and durability and so on and so forth. The better fighter is the one who can combine ALL attributes and beat their opponent. If I'm less skilled than you, but I can beat you via being bigger and stronger, then I'm still a better fighter than you, just like if I'm less skilled than you as a sprinter, but I can out run you by being way taller with longer strides, then I'm the better sprinter.