I’m not a legal expert, but I’m pretty sure that County Sheriffs are elected by the “electors” [registered voters] of each county, and answer to them. California has some quirks about the State Attorney General having authority of some sort over the cope of what Sheriffs do. That does not mean the AG can fire, suspend, or replace Sheriffs at will. The LA County Supervisors are acting unconstitutionally. Sheriff should arrest, and quickly shoot, them for conspiracy, attempted coup, and insurrection.
Sounds to me like interference with a peace officer in the performance of his official duties.
Issue the relevant citations and bring them to court.