There is so much overlap in school age kids where there are males that would hardly be competitive on the female teams and some females that could reasonably compete on a male team. Almost no one is "average" in reality.Me (an average male basketball player) playing against the best female basketball players in high school and jr high and dominating them is absolutely true. They had no chance against me.
As for the average male not being similar to the average female in physical nature google agrees with me. Average male is 5 feet 9 inches and 197 lbs. Average female is 5 feet 4 inches and 170 lbs. Those height and weight disparties would never be allowed to box or wrestle or compete in mma against each other for a reason. That doesn't take into account the other differences such as coordination, leaping ability, strength, speed, etc that the average male is also superior in comparison to the average female.
But that's not even the important part of what you're saying. You are making a mistaken assumption that a transgender female is simply a male who makes a verbal declaration that they are female and therefore wish to play on the female teams. I'm going to again avoid getting into how absolutely unlikely it is that a person would publicly identify as a female simply so that they could participate in female sports and focus on something that I think you might be missing... Testosterone. No, I'm not saying you're low on testosterone. But almost all transgender females are on testosterone blockers. That's why I said "within reason*" in an earlier post. Because I think there should be some length of time from when a transgender female begins taking HRTs (testosterone blockers included for transgender females) and when they can start participating in sports as a female. I don't know what other criteria should, could or might be considered, and that's why I left the "reasonable*" part vauge.
The average male to female transgender person who has been on HRT medication is not just a male dressed up as a female. That transgender female would not be anything close to the average male in physical strength even if they were the prototypical "average" male previously.
And I love you man, but this again is an argument from the position that transgender females are lying about who they are. That in reality they are just males dressed up as females.
There is a very real difference between someone in drag and someone who is transgender.