Leagues are irrelevent in playoff division groupings. Per CIF:
"For your information, we no longer will be using league based playoff groupings. Instead, individual schools will be evaluated and placed into divisions on a yearly basis for the sport of baseball utilizing a formula which includes the following factors: regular season record, strength of schedule and CIF Southern Section playoff performance over a two-year period."
Based on their "competitive-equity formula", J Serra was #1, OLu #4, MD #10, SMCHS #17 and Servite just made the Div. 1 cutoff at #42. SJB was #48, thus D-2.