At their peak, the average woman has the aerobic capacity of a 50-year old male???
This is hogwash on steroids. Women runners at any local 10K will come in minutes ahead of the 50-year-old men. Aerobic capacity is women's strong point. Women do relatively better at endurance sports (distance swimming, marathons, etc.) than at, say, weightlifting.
Giving specious and ill-informed reasons why women should not serve in combat works against the needed cold realism that should inform our decisions about how to fight our wars. If there are good reasons why women should not be integrated into line infantry positions, say, they will be lost in the flap that will arise over the bad reasons.