They're not actually chalk and cheese though mate, Williams is currently comfortably the better defender and he's strong on the ball too. He's not as strong in possession as Stones, and he won't dribble out the back the way Stones does, but he's not weak in possession.
Just irritated me seeing that link, knowing that, in the short term at least, should both moves go through they'll be guaranteed an upgrade on Stones and we'll be paying for him and they'll still have tens of millions to spare as well.
I see the rationale in signing Stones, don't get me wrong, I just have real doubts about the move.