Being the best team doesn't mean they gonna win the WC. May be but who knows. Thats why they are playing world cup else they would have given the trophy based on fifa rankings. And please Avoid bringing club statistics when it comes to WC coz all those players whom you mentioned (Gabi, Isco, Carvajal, Raul Garcia) who didn't make to WC, played in the CL finals.
I think their strikers are one of the weakest among the contenders. Costa's fitness is unsure. Villa n Pedro are mediocre and forget abt Torres.