Sometimes what you are targeting is too large or small to use the standard randomization chart. To this end the following is submitted to the proving grounds.
Horses and riders pose a problem, as the horse is considerably larger than the rider most of the time. Therefore, the 50/50 ratio would not be appropriate to hitting the rider. In this case, before the random chart for limbs is done, first roll the following to determine if the target hit is the horse or the rider.
Horse hit chart 1,2 = rider / 3,4,5,6 horse
Play test this a bit and let us know how it works in your games!