1. A vehicle control apparatus for a vehicle, the apparatus comprising: a target value calculation section to calculate a target value relative to a vehicle behavior of the vehicle; a control section to cause a plurality of instruments to operate in cooperation according to the target value relative to the vehicle behavior to control the vehicle behavior of the vehicle; a first physical quantity detection section to detect a first physical quantity relative to an actual vehicle behavior of the vehicle; a first determination section to determine whether a separation arises between a target vehicle behavior and an actual vehicle behavior of the vehicle based on the target value relative to the vehicle behavior calculated by the target value calculation section and the first physical quantity relative to the actual vehicle behavior detected by the first physical quantity detection section; an instrument behavior estimation section to estimate an estimated instrument behavior of a behavior estimated instrument that includes at least one instrument among the plurality of instruments, the estimated instrument behavior being demonstrated when the behavior estimated instrument is caused by the control section to operate in cooperation according to the target value; a second physical quantity detection section to detect a second physical quantity relative to an actual instrument behavior demonstrated by the behavior estimated instrument whose instrument behavior is estimated by the instrument behavior estimation section; and a second determination section to determine with respect to the behavior estimated instrument whether a separation is exhibited between an estimated instrument behavior and an actual instrument behavior based on the estimated instrument behavior estimated by the instrument behavior estimation section and the second physical quantity relative to the actual instrument behavior detected by the second physical quantity detection section, the control section being further configured to bring the actual vehicle behavior close to the target vehicle behavior by changing operations of the plurality of instruments according to a magnitude of the separation exhibited in the behavior estimated instrument when (i) the first determination section determines that a separation is exhibited in the vehicle between the target vehicle behavior and the actual vehicle behavior, and, simultaneously, (ii) the second determination section determines that the separation is exhibited in the behavior estimated instrument between the estimated instrument behavior and the actual instrument behavior.