well, I'm not 100% on the maths, ( meaning I have never troubled myself to find out ), but the principle is easily demonstrated.
block up the front end and take out the wheel. Now, turn the bars. With the caliper above the axis ( in front of the leg ), the weight of the caliper will tend to swing the leg to the stop. With the caliper behind the leg, it will act as a pendulum and tend to centre the fork again. The heavier the fork leg relative to the caliper, the less the effect is, obviously. Likewise, the shallower the fork angle, the less the effect; a vertical leg will not react one way or the other.
there are a whole range of variables, the weight of the fork assembly is one, the weight of the wheel assembly, the fork angle, you get the idea anyway. Triumph and Ducati did a lot of work on this in the 70s. Most 70s production bikes had the caliper in front of the fork because it's easier to assemble and service, but if you have a quick flick around in Google images you will see that behind the leg is now usual, and this is the reason, ie handling.
I've never much liked 3.00 x 21" wheels on Big Twins, I think they are inadequate in terms of tyre contact patch for the weight of the machine, so I expect you are right about the wheel tending to skid under braking
Mongo only pawn in game of life