Once again, I have to argue with you on performance specs. First of all, for towing, horsepower means jack shit. Second of all, the torque value IS important but so it the RPMs at which those torque values are developed. A hypothetical example...an engine that produces 300lb-ft of torque at 1200RPMs is vastly superior to one that produces 350lb-ft at 4500RPMs. You undervalue the 300 six by not recognizing the uber low RPMs it developed its torque figures at.
No, I’m undervaluing the 400M engine. People don’t wonder why Ford had the 300/6. They wonder why Ford bothered with the 400.
Further, I’d like to flip back a point you made earlier - gearing can move that power around to a more usable point anyway.