Dave,
You've gone thick again. Time to cool down!
You said something that shows where you've gone so wrong,
"Your example used the optimal lateral flight speed for minimum main rotor power. You know that at maximum speeds and/or yaw rates the horsepower demands will be higher."
Dave, the power that the TR equipped aircraft needs is highest in a steady hover. As the aircraft accelerates sideward, and the TR begins to need more power, the MR needs far less. The result is that you "new" discovery that a TR can consume 500 HP is both true, and irrelevant to your search for greater efficiency through symmetry in all things.
Gordon Leishman is very good, and he is also right. His statement is not a condemnation of the TR, it simply admits that, in the world of hard reality, where only internet posters get to live their dreams, all others must build stuff that works.
As Churchill explained, “
It has been said that democracy is the worst form of government except all the others that have been tried.” He could have been talking about tail rotors.