In Capital in the Twenty-First Century Piketty suggests that if the return on capital is higher than the economic growth, then wealth inequality in society will rise.
Yet, this model seems to ignore that people leave their inheritance to more than one person on average and form marriges with people of not ideally equal wealth. I.e. if a billionare marries a millionare and have three children to whom they pass their wealth after 50 years, they'll pass $\frac{$1000m+$1m}{3}(1+r)^{50}$ to each of them, making the society more equal if r is small enough.
Does such effect of inheritances break the model's conclusions (and inequality may decrease when r is significantly higher than g) or the effect is negligible?