Bill,
Your idea about the electric pump and more flow at lower speeds is pretty close to the mark.
I went to a Meziere electric and had some folks in Texas at Hollister Road Co. Make up a pump and fan management gizmo. They call it a
Pulse Width Modulated Fan and Water Pump Control Unit <=clickable.
You can read the whole smash on their site but this is the gist of how it works. When you start the car only the water pump comes on at less than full blast. It's job is to circulate the coolant so no hot spots develop on warm up. As engine temperature comes up the fan(s) come on and both the fan(s) and water pump seamlessly vary their speed up and down under the control of the gizmo to maintain a target engine temperature you set.
At highway speeds if the fans are not needed they are turned down or shut off. When you park the car the fan and water pump run on for a minute or so to help the engine during cool down. The system uses no t-stat at all. Instead there is a temp sensor in the return hose to the radiator that the gizmo uses to measure engine coolant temperature and decide what the fan and water pump should be doing. It is a very nice closed loop system that works extraordinarily well.
Ed