>"Concretely it absorbed an excess of male heirs so they could live a comfy life and would not try an hostile takeover over their elder brothers' state."

That was often a consequence, but in general it provided an alternative pathway to male success in life and a means of advancing through a respected status hierarchy that did not depend on the traditional markers. Something sorely lacking today, when even outside the question of inheritance you are faced with the near impossibility of achieving the economically independent and socially valuable life that your grandfather or father had by simply working.