Except go the whole tour without losing much time, which is a damn good achievement. As I’ve said, I don’t think he has the spark likely to win him the TdF but what he does achieve is something outstanding.
Sagan at Rio will be great for MTBing. Fascinated to see how he gets on - His national stuff was pretty underwhelming, so either he was just a bit rusty or the disciplines have truly diverged and he’s just not adapted to MTBing any more. He is the best bike racer on earth, though, so we shall see.
Sven Nys was the greatest cyclocross rider of his generation and ‘only’ top ten in MTBing - think he did one olympics. XC MTBing is way less technical than CX though, so his edge there would have been neutralised. Sagan is coming the other way from the road, so it’s tempting to think he can just obliterate the field with power. The rapid on/off redline efforts of MTB racing are very different though, so he may not be able to dominate.