For purposes of ECNL, not a big deal for purposes of allowing trans girls to play with other girls. If a 17 year old girl can't be competitive against a team that has a trans player, that's too bad for them and they're not good enough to play in college anyway. Never in history has a trans girl dominated ECNL, and never in history will one.
Now, if you're going to create fake hypotheticals about what might happen if your 17 year old daughter fought a trans girl in MMA, well that's another story. Same if you speculate, like someone else did, that an entire team of transphobic shitbags might enter into a girls soccer tournament, the club lets the team happen, the tournament lets them in, and then the opposing team plays them (none of which will ever fucking btw), then that would be a problem. But we're not talking fantasyland, we are talking reality. In the end, you and your transphobic friends just need to keep making up fake impossible hypotheticals because the things that are actually happening contradict all of your fears.
It's funny how you and your transphobic friends keep saying I don't make sense, although all I keep saying are the things that ECNL, and the NCAA, the State of California and others keep saying to explain why trans players are allowed to participate. But you think fully grown adults who are afraid of 12 year old (or any age) trans girls are the sane ones? You think fully grown adults who lose their minds over the possibility that their 12 year old princess might not win a soccer trophy are the sane ones? The guy who tried to publicly out a 12 year old girl who "looked trans" is sane? The guy who claims that trans girls who are playing in compliance with the rules set by a private f**king company are "cheaters" is sane? Sure. Honestly, all you and your friends keep doing is proving how important it is to continue fostering environments that prioritize inclusivity over whatever toxic rah rah "sanctity of sport" bs you keep whining about.