I wonder if you'd end up potentially getting the
oil too cool.
My thinking here is that you'd be designing the system to maintain a specific water temperature, 180 degrees for example. The water in the radiator would average out to some temperature around 180 degrees once the engine had warmed up.
Depending on how much time the
oil spent in the 180 degree temperature, wouldn't the
oil temperature normalize at some temperature around 180 degrees also?
(Gross oversimplification and a whole lot of swag going on ... and I haven't the foggiest idea of what I am talking about!)