Thats just it though. The right equipment. Nobody except BMW, Ferrari, Mclaren and Renault have the right equipment. On a standard day, the top 8 will be from those teams, Ferrari/Mclaren occupying the top four, BMW and Renault the bottom four.
Its like when Spyker said they got rid of Albers for not being good enough, but kept Sutil. From what I've seen, they're both not much better than backmarkers, so it doesn't matter who's in that car, they won't finish in the points. Ditto Liuzzi and Speed, they're both not good enough, but we won't know for sure until they get one of the four aforementioned cars, because none of the others are even on the same level competitively (with the possible exception of RBR on a good day)