Alberto had the Tour before doing the double, but then had two in a row. Menchov, Basso, Valverde, Nibali and Sastre all did it within a couple of years. DiLuca somewhat before. Evans of course did it too. It might be a good experience to feel that riding for real and trying to compete on empty. Perhaps the body can't be topped up as much nowadays so the toughening is necessary to pull through, more like the older days.
Much has been made of the fact that one can't win the Giro - Tour double nowadays, but I noticed an interesting fact: In the last five years every winner has ridden two Grand tours in a Year sometime, generally before some of their victories.
So given Evans doesn't fall off tomorrow we got
Evans, Contador, Nibali, Basso, Valverde, Menchov, Sastre and DiLuca as the only GT winners in the last five years (since 2007 year). Kind of interesting.
Notice something? These guys rode a lot. And rode a lot to win. Different from the Armstrong days I think.
So I think the appeals to Andy Schleck to ride some week long tours and some other races hard has some truth to it.
I don't think it is total co-incidence.