The skilful style of play of all these, is of a sort where they need to be on top form to be fully effective. They will all have periods when they are off form. Even Messi and Ronaldo have had periods when they have been relatively ineffective.
The sort of player who gets by on "work rate" will be much more consistent - but wont be able to offer the moments of magic which skill players can.
Players such as Silva, Hazard, Kagawa, and Cazorla cannot be judged on the basis of just a few games. Which is why at present as far as the EPL is concerned, it's still Silva first and the rest nowhere.