Inaccuracies in what way?  The fractions?  Note that your diagram shows 3/8 and 5/8 as the proportions, but by my calculations, C gets 8/24=1/3 and B gets 16/24=2/3.  I don't know how you got 3/8.

My main point here is that I want to keep the example as minimal as possible.  The people that need to understand this might have to sit down and draw a picture for themselves, but I think that's OK.  The problem is for those who are reading this to get a general sense of the problem; I don't want to have them wade through all this detail.