Earlier quoted context omitted.
Maybe? Certainly more offspring was normal, the further back you go. So wealth division could more easily happen. But most cultures had the idea of the "first born", the official heir... for this very reason! Most of the loot, holdings, tended to go the eldest.
This is no longer legal in many jurisdictions. Family members often have a minimum allocation of the inheritance (e.g. 25% must be equally split among all children)
Yet the proverb is historical, as all proverbs are, and my response was intended to refute the dissolution of wealth, historically, by spreading it too thin.
Our ancestors didn't do that.