I looked through the code, and apparently the calculations aren't actually as stated. The trait values are combined as per the patch notes, then the value is entered into a weighted randomizer. The higher the final calculated value of the parents' traits, the higher the chance to get a good result, but bad results are still likely, and vice versa...
Like how I just bred a stunningly good looking child from two hideous parents as a test, which at the lowest weighting parameter for beauty is .025, or 2.5%.
Even if both parents have the best values for their trait for beauty, their child having that same highest beauty is 25%, repeating for each variable for 25% (cock, bust, beauty) or 50% for all other traits (when both parents have highest value)... Soo, my plan to create a single slave with maxed out stats is basically a pipe dream, orz...
That is, unless I tweak the values myself... *shifty eyes*