I disagree. In fact, what you are saying is something Colo does quite frequently, "bite" when a forward drops a little deeper to collect the ball or lay it off to a runner, and it's a situation where the defender is quite easily turned or simply caught out leaving the centre of defence wide open. Didn't Southampton score their fourth from such a situation? Again, I haven't seen the goal, so maybe it looks worse in motion, but in that still his position isn't all that bad.