So in theory it can. But like I said we need
1. position
2. orientaiton
kinect alone will not give you orientation so when hand is tracked by kinect only and you rotate hand you will not see that controller rotate. unless someone someday will write robust tracking of hand position by kinect 🙂
I made some tricks for leap motion that allow you grab elements from behind. did u try that ? but yes, leap motion alone has limitations. i am not planning right now merging leap motion and kinect cause I am not sure how it would work from the orientation perspective.
Kinect One is new and has better presicion.