Value of chicken matriarchs

I've been reading about how important old, wise matriarchs are to elephant herds.  (Bear with me here --- this really is relevant to chickens.)  If you're an elephant, you scoff at lone female lions, but male lions are half again as big.  While it would take about seven lionesses to kill a full-size elephant, two male lions could do the same job and it's conceivable that a single male lion could take down an elephant in a pinch.

Until recently, humans couldn't tell the difference between the roar of a male and female lion, but modern digital magic has shown us what the oldest elephant matriarchs knew all along --- the sounds are subtly different.  Scientists played recordings of roars from male lions or female lions to various herds of elephants, some of which had old matriarchs and others of which had younger matriarchs.  Only herds led by elephants who had reached or surpassed their sixtieth year reacted more to the higher danger male lion roar than to the lower danger female lion roar.  Perhaps the younger elephants couldn't tell the difference, or just hadn't been around long enough to discover how potent a single male lion can be.  Other studies have shown that herds of elephants led by an older matriarch are better able to survive droughts and to avoid bee stings.

Reading about the importance of these old elephants got me wondering about whether we should keep our oldest hens in the flock even though their egg production has slowed down.  I have high hopes that by this fall, some of our homegrown chicks will be overflowing our egg basket.  At the same time our then nearly six-year-old hens will be molting and settling in for a long winter of eating me out of house and home.  I had originally planned to whittle down the flock to delete these old sit-abouts, but when I watch our chickens on pasture, I can tell that the oldest hens have a lot more foraging tricks up their sleeves than the youngsters do.  Mark threw a crawdad into the pasture the other day, and one of the old girls tore into the tasty treat while the younger hens looked on with confusion.

I think there's a happy middle ground between the most efficient chicken-keepers who kill hens as soon as they reach three years old and the least efficient chicken-keepers who let their coop turn into an old chickens' rest home.  Perhaps maintaining at least two matriarchs should be part of my strategy for building the best foraging chicken flock?