it would only make some sense if this was the guys first relationship....I can see the stock piling of financial assets to support a young family....
but if the old guys go for the young ones, whats left for the young guys?...they are at their prime sexually and physically and what do you expect them to to while fat bald grandpa dates young women....twiddle his fingers?
there is a reason why men naturally loose their ability to perform, etc.....its natures way of saying "enough"....its natures way of saying we need new genes from the young and healthy guys...
i like the way you think!
What do the younger guys do? Historically they try to build up their resources. Most or at least many males maintain their fertility right up until death. It is thought by some evolutionary biologists that such pairings over time lengthened human lifespans. Those fit enough to live to an older age passed on their genes to their offspring.