Yes, the unrivaled, unparalleled Cadel "never won a GT mountain stage" Evans
Not sure how relevant this is either. GT mountain stages are not easy to win (for example, outside of 97 did Ullrich win any?), and were probably even more so in Cadel's era (compared to today) when there were arguably less of them, and when they tended to be a little more queen stageish in difficulty.
What's more, Cadel's consistency didn't allow him the opportunity to win them from a breakaway, and for the most part he was a marked rider.
Looking back on 2011 Contador, maybe the double didn't really effect him? This is pre ban Contador, and he hadn't tried the Giro-Tour double at another time to compare. So maybe it was more about those early Tour crashes?
Regardless, 2011 Giro Contador is a higher level than 2011 Tour Evans. Just how much better is hard to say, but probably not five minutes.
P.S. As for Wiggins and Klöden, I think we're talking possible podium rather than victory. As pointed out, Evans' ITT was very strong, and just where do they hope to gain time (assuming that they manage to hold on during every mountain stage, which is quite questionable)? I don't see either rider attacking with Schleck on Luz Ardiden or Izoard (it wasn't really their mentality, even if they had the legs). I can see them working with Cadel on Galibier, but that only helps Cadel, and reduces the gap to Andy (reinforcing their hypothetical podium chances).