"Dont agree with that. To reach 6 inches you will only need to rise 5 inches."
Fine, but you had said rise 6 inches.
"to reach 5 inches I raise by 2 inches."
So now we have risen vastly unequal amounts in the feet (5 inches for me, only 2 inches for you), in a way that makes you, as the lady, always have substantially less rise and fall there than me. In some situations that will work, in others it certainly won't.
Thus the fundamental problem: you cannot define either a correct altitude or a correct ankle angle, without taking the situation into account. Your attempt to ignore the situation was how we got into this argument in the first place.
You have to learn to pay attention to context.