The biggest problem here is umpires not being consistent in the way this is enforced, much like the look back rule. So much of the time, teams who push the bases hard will "get halfway" leading to a pitcher, who is the circle to act like she will throw. Sometimes this draws a throw and some times it does not. The only point I was trying to make is if the pitcher is on the rubber with the ball in her hand taking a sign, no one can advance at that point. Simply being in the circle with the ball is not enough to stop a base runner from advancing.
The original post was about the catcher running at the base runner who is half way. Simply throwing back to the pitcher, in the circle, makes the runner make a decision, however that decision might be to advance to the next base. The catcher who runs at the base runner freezes the runner and then can simply hand the ball to the pitcher, who is in the circle and ready for the next pitch. Faking a throw by the pitcher is not enough. This kind of stuff is a non issue at the older ages as the throws are laser accurate and any runner who tries a delayed steal is likely out. This type of stuff happens more frequently at the younger ages.