the position of a brake caliper has the same affect on the torque generated as the shape of a spanner has on the torque it applies.
it might be bent, it might be straight, it might be thick, it might be thin, it might be hollow, it might be solid, but the torque generated around the point of rotation is equal to the (input force) x (the perpendicular distance).
input force = the deceleration force on the contact patch of the tyre.
the perpendicular distance = the vertical height of the pivot above the ground.
everything inbetween the contact patch, and the pivot, is just a funny looking bent-spanner.
caliper postion has no effect.
i've come to appreciate brake-squatty single-pivot bikes, a big handful of rear brake and the back end sits down a touch = they're less nose divey than true brake-neutral bikes*.
(*which i also like - you can brake through really heavy braking bumps and simply not feel them, everything is good, but for different reasons: i might suggest that slow steep and techy trails might suit a single pivot, and rumble-strip alpine Dh tracks might suit a parallelogram design, i might suggest this, but that would start another massive argument )