I've understood your simplifications, but my lack of knowledge is on the linearity of the torque/thrust relation from 15% to 75% Q. Also, at any torque from 15% (operational NR, I don't know if the Apache works at 100, 105, 107%...) the torque required to drive the MGB and accessories (assuming constant generators loads etc) is the same, but the torque used to drive the TR increases (and again I don't know the relation between them).