Yeah, cooling systems aren’t buffered like they used to be. Around town the electric fan typically provides air flow that would not otherwise be possible at a given engine rpm.
Side note on interesting trans cooling modalities: One Toyota pickup with HD trans cooler (I assume it’s a Tundra) ONLY engages the air:fluid auxiliary rad up front when the converter is unlocked. When in lockup the system reverts to engine coolant fed directly from (something like) the heater circuit locally at the trans. No in rad cooler tank at all. One thermostat controls both engine and trans. It’s very much like the sandwich laminar coolers found on some 80’s Fords and many Euro’s through today.
The only true advantage I see for the lockup converter (other than eliminating unnecessary heat) is that it can allow a really high stall converter to compensate for lower powered engines without paying on the other end. Otherwise, just throw in higher gearing for economy’s sake. It may not deliver quite as much drivability …but …SO?
I often thought a trans composed of a series of converters with lockups would be more reliable than the CV transmissions. Virtually unlimited torque and low losses at cruise.