So it seems to me:
Overall lock
Clovis West
Southern locks
Long Beach Poly
Harvard-Westlake
Troy
Etiwanda
Mission Hills
Northern locks
Mitty
Pinewood
SMS
Carondelet
Southern candidates
Bishop's
Fairfax
Northern candidates
Sacred Heart Cathedral
Salesian
Bishop O'Dowd
Cardinal Newman
Miramonte
McClatchy
Vanden
Given that list, I'd guess Clovis West goes South because there are fewer candidates there making it six teams... Bishop's and Fairfax have pretty much the same rating, so I think they go eight or six. But of course you never know. If it's seven, it's Fairfax.
That leaves the North with four locks, and rumor has it SHC has checked the box saying it wants to be in the Open. Let's say that's true, or that SHC is pulled up.
Of the remaining group, a maximum of three will go -- and my feeling, based on nothing, is that if the South goes eight, so will the North. If the South goes six, so will the North, and the South is the driver here because fewer options are available (they can only take four Southern Section teams but if they could take more, the equation would change).
Let's say it's eight. By record, section title and ranking, Cardinal Newman is in, making six.
Now it gets hard:
Salesian: Section champ, quality wins, but eight losses and lowest MaxPreps rating.
Bishop O'Dowd: Record and ranking are positives, big wins (Pinewood), but not a section champ.
If the committee wants O'Dowd, they pretty much have to take Salesian, which would fill the bracket.
If the committee decides to pass on O'Dowd, then Salesian isn't an automatic (and both go into D3 to likely meet again). Now on the table are Miramonte, McClatchy and Vanden. Of that trio, Miramonte has the record, the ranking and section title, and is in. McClatchy/Vanden? Flip a coin, or stay at seven.
If the committee takes Salesian and passes on O'Dowd, then it would make sense to stay at seven, since O'Dowd has more credentials than Miramonte (won the TOC bracket Miramonte finished third in, not to mention bigger wins).
The easy path? Stay at six in both North and South. That strengthens the lower divisions and gives byes to the top two teams in each region.
Go beyond six, and it gets complicated ...