User blog comment:Master Sima Yi/Assassinews 10-05'12 — World Gameplay Premiere/@comment-3206933-20120512181529/@comment-1888015-20120515171426

If you think about it as well, having Eagle Vision/Sense pick up Wind Direction could influence the arrows fired from a bow, so it can be aimed better.

It could also allow him to know where his scent is coming from, so he could stay downwind of animals when he hunts them.