One thing is for sure. There is a big gap in this age between the top 2 and the rest. 91 will likely fall closer to the top 2 once they play. But everyone else is going to tighten up below this AA tier. That's not to say all the other teams aren't good, it's just those top 2 or 3 are really freaking good.
My biggest complaint about youth lacrosse after watching this over many years, with my three boys in varying classes: that there are almost always a (small) bunch of very good teams at the top but then the next GROUP down is treated like pariahs - the "everyone else is B" crowd, if you will. Your assessment is a better, objective take on this: there are the AA, and then there are A teams, and then B etc.
Far worse than this is the disparate ages of the kids competing, in a system where age is irrelevant. I have had multiple kids play and never once have I ever been asked for their age or DOB, and for that matter, proof of their grade. What the movers and shakers of travel lacrosse don't get is that this lack of age enforcement (or indeed, the lack of age even being relevant) drives people away. Travel hockey, which is fanatical in its age enforcement, has a much deeper pool of competitive levels, and therefore, paying customers, because once you ensure the kids are similar in age, you can do much more in terms of subdividing based on skill and athleticism.
Yes, the age thing is my second biggest complaint, and it is largely a driver as to why tourneys and teams are unable to properly 'position' themselves. Hockey has done all of the heavy lifting here, so USL wouldn't have to do much more than 'steal' their model, other than with a few tweaks here and there (you can do away with the player-team exclusivity, for one).