I agree that having an 8 year old playing a 6 year old is pretty bizarre. My point is most “holdbacks” are not 2 years older then the kids they play. More likely the kid was born in June or July so he is on average maybe 4 to 8 months older. The problem I have is you conflate your 2 year age example and smear it evenly across all so called “holdbacks” as if - 2 yeaa as r age difference is common when it is the exception.

For kids who are a few months early of your magic September cut off date, please do not judge them or the their folks until you walk a mile in their shoes.