Does This Debunk the "Coolant Can Flow Through the Radiator Too Fast" Idea???

The best way for me to think about it is that heat transfer rates are not linear. The radiator dissipates more heat when the difference in temp between the coolant and ambient is greater. In other words, the sooner you can get the hot coolant to the radiator, the better. Plus there are diminishing returns the longer you keep the coolant in the radiator. Flow is your friend in this case.