OK465,
I don't disagree with what you are writing, but it does not change the physical law that increasing the V/S requires a vertical force that exceeds the weight of the airplane.
Secondly, the airspeed will increase or decrease at any instant during the transition at which the thrust is greater or less than that required to sustain the FPA at that instant. Therefore the FPA has to increase faster than the thrust to avoid any speed increase during the transition.