You can slice the numbers in different ways but they point in one direction. You are right about the impact of DA though, particularly on ECNL. The top SW ECNL teams are still very good (as evidenced from the results in Silverlakes and Surf College Cup), but I'm seeing some poor results at the bottom. I suspect with the same analysis you'd see an even greater hit to the goal differential gap in the Southwest division over the past year. In any event, this is yet another argument for why the formation of DA on the girls side is not necessary a good thing for overall player development in the US.I think you have provided some very interesting data. Certainly holes can be poked in the specifics. For example there has been a ton of player movement so its hard to compare one year to another. Still I agree that the introduction of DA and new ECNL teams has diluted the talent for the lower leagues. The introduction of DPL has also diluted the level of teams in the remaining SCDSL and CSL. The same could be said for how SCDSL hurt CSL when it was formed several years ago. At the end of the day though the fall leagues are only about 10 out of the 40 plus games that these teams play in a year. So there is still plenty of opportunity to play against each other. National Cup will also bring these three leagues together.
Further, this a discussion about leagues so the fact that there may be playing opportunities outside of the leagues is somewhat beside the point. And the National Cup matchups are very fluky. Not a good example of having other guaranteed opportunities for a consistent/equal level of competition. Moreover, the fact that a decision adverse to player development may have been made in the past doesn't mean we should repeat it.
P.S. I sincerely hope none of the families on your daughter's team are affected by the fires. And may God bless everyone who is impacted.