I have no knowledge of U.S horsepower vs. Euro in DIN so I will not comment on the analogy; I’ll assume your comment is correct.
As for the FCC vs. JEITA, It was not my not intention to suggest one was better than the other, even though everything I have read over the years suggest the FCC specifications are more accurate and transparent.

Those who have long enjoyed such privileges as we enjoy forget in time that men died to win them.