Wonderful solution.. But i feel something is wrong with the probability part. Since random numbers are being generated it might not reveal the true sense of probability. I think, it would make much sense if you could count the number of shots made by each person example conside 10 as the base. So Charlie makes 9 perfect shots , bob makes 5 perfect shots, and aron 3.33 (or 4). Reset the count when one man standing. Random pick the shots and remove them.

just a little logic. Might or Might not work. Hope that helps. wont be able to help out with the codes been a while.