I don't think he knows, but neither did Moyes or Martinez or the others.We have to give him time till we see his preferred 11 in the team and then we can judge. Right now what could cost him so the lack of replacement gana and Zomua. Can we really blame silva for this?
What is Silva first 11 if everyone is fit and ready to play.
They all have one thing in common, they try to put their favourite 'best system' on to different permutations of 11. Which when you think about it can't work, except in the odd stopped clock is right twice a day way
Pick your 11 first, then the best system that suits them