Very good point! However, the LA squad that went on a tear in the play-offs was a completely different team than when they lost those three games. (I'm sure you can find a few games that prove your point with healthy 5A teams beating healthy 8A teams, though)
At the end of the day, there are classes for a reason. If the 8A champ happens to go undefeated and win state, they deserve #1. However, in almost any other circumstance, it's up for debate!
Regarding end of season rankings, Naz's whooping at the hands of Marist last season would make #1 questionable (don't recall what Edgy had them at). Regarding pre-season rankings, their new addition at WR & JJ make #1 reasonable.