He's right no it won't improve the cooling situation.

But he's wrong that it will make it worse, because you CAN get electric fans that move as much air as OEM.

The only improvement and electric fan will have, and its a very very minor almost non existent one on a V8 engine, is lack of parasitic drag at idle compared to the clutch. On a car like the 190E 2.3 on the other hand the difference is very dramatic especially in stop and go traffic, three guesses how I know