I'd say you're completely wrong; I'd go as far as to say that water is the MOST POWERFUL nature release in Naruto, just Kishi hasn't used it to its full potential.
A reasonably good water element user should be able to manipulate the water around him to a certain extent right, and be able to draw it towards himself?? A master can create water out of nothing (Kisame's Water Prison), so I don't think it's a stretch to assume a good water element user can manipulate the water around him. Now the point I'm making:
Why not manipulate the water in the opponent's body (65% of the human body is water)? Point proven, now close thread.