Look Im a great exponent of having a settled side and playing your best 11 week in week out. But I accept that for the League Cup (which I always maintain PL clubs shouldnt enter) you can put a changed side out.
During the course of a season, you can change the team for suspensions, injuries and loss of form but, I think the extent to which Benitez changes the side, especially in the PL, makes a sustained challenge difficult to say the least.
Small changes maybe, wholesale changes like in the past, no.