Distance is clearly (and should) be a factor in the number of AAA teams. SoCal is big. But I don't think that means having 5 at 18AAA in SoCal though, when two of the three 16AAA teams feeding those teams last year in SoCal were frankly really bad :-)
It's a balance. And CAHA does have to play a role. It can't be a free-for-all.
What I have seen (over and over ... I'm not speculating ) is those AA kids that are put on AAA teams to 'fill' them have miserable years. They are stuck on the 3rd line and/or hidden as wingers and get 2-3 shifts a period on average (at best). Because AAA is always going to be a lot about winning (if not AAA, then where does winning matter?). They can't keep up in practices, and honestly, in %80 of the cases I've seen, they last 1 year in AAA and go back to AA. They aren't helping the team, apart from numbers, and aren't helping themselves. If it's exposure they are looking for, that's not the exposure you want. They just look bad.
Compare that to being a first line player in AA, and getting huge amounts of ice time playing with their peers. That's how you develop players.
There are always going to be marginal AAA players at the bottom of lineups. The question is how many. That's just math. How many teams, and how many kids good enough. How do you know when they are ready? They actually make a reasonable team, at tryouts.