There are engineering studies that show how the heat transfer coefficient changes. It is not linear in all ranges with flow. Just like hp and torque curves fall off. It would be optimized in a system design. Heat transfer is a rate right? One molecule of water moving through the radiator at the speed of sound would cool less then one moving a 10mph. At higher speeds it is in the cool zone less. Of course the next molecule in would probably be hotter then the one in front because it is a closed loop. Obviously the goal is keeping the engine at the correct operating temp during various uncontrollable conditions like winter versus summer.
Just because something is non-linear, does not mean that it has an inflection point and decreases over a specific value. The rest of those analogies aren't even relevant.
This is probably some of the best compiled cooling system information on the internet; Stewart did a ton of testing on stock car/NASCAR engines and posted some of their findings, unfortunately only the summaries are still available.
https://www.stewartcomponents.com/index.php?route=information/information&information_id=14I never commented on the original post regarding why A/C cars are over-driven and non-A/C cars are under driven. It has everything to do with the fan speed. Due to the condenser being in front of the radiator (higher pressure drop through the stacked cores) and also the need to have airflow for the A/C to work at low car speeds (e.g., sitting in traffic), the water pump pulley was overdriven to spin the fan quicker.
Now... for using a 22" radiator to cool the big block. Hopefully cleaning this one out works, but if not, find a radiator that has the widest tubes possible and most tube-to-fin contact area. Unfortunately, this is where expensive radiators earn their keep over the cheaper ones. The hotter you keep the radiator fins due to their contact with the coolant tubes, the more heat will get transferred to the air stream. Aluminum is stronger than copper, so the AL radiators can run larger tubes and get significantly more fin contact area. For example... three rows of 9/16" tubes = 1-11/16" of tube/fin contact length. A radiator with two rows of 1" aluminum tubes likely fits in the same core spot and gets 2" of tube/fin contact. Radiator core design can be a bit tricky, because if you just increase thickness, the pressure drop across the air side increases, which then decreases fan flow and is counter productive... most of the expensive units have figured this out.
