What Australia style purge?
Anyway, English selectors have to be brave but their idiocy has already driven Plunkett and Rashid from the longer format of the game. Fast bowlers may be replaced, although the way Porter is being roundly ignored, Finn has been treated like trash for years, I don't have many hopes in that department.
Then we get to the batting where Cook's clout is such that he will likely play another season, Root can keep throwing unprepared pups into the lion's den at 3 and still be lauded and no true opener of world class quality has been found.
Having said that, in home conditions, they should still be good enough to beat this years tourists.