>>How can a team justifiably fit between great oak and Oakdale when they were so close<<
Well, you have a committee to decide those things. Looks like they thought those 3 teams were about equally worthy. But only 2 spots, so who goes? Well, the merge dictates Great Oak over Oakdale. Then a coin flip for the last spot, and the fact that California got 2 at-larges last year may have played into the decision.
I would have picked Oakdale, but that's because I would just use the regionals, and they were clearly better for that week. But that only solves this year. Many years you still have the problem of teams that look fairly equal, but never competed head to head. How do you decide? Well, you have a committee that decides.