Strictly looking at the torque curve for the new hi torque motor you might be right. However also looking at the newer motors torque curve is very misleading as it peaks around 1600 RPM and drops like a rock the higher you go. Unlike the older 6.7L's flat torque curve.
There is also some misinformation it appears about the two transmissions ratios. Comparing the two they are almost identical with first second and third slightly different. At the end of the day transmission choice will make no difference.