They touch on the ability to directly compare Orange County to Los Angeles County pretty well in the article, even admitting it’s a better comparison than Bay Area county comparisons.

Orange County — a non-mask-mandate county — had a very similar outcome to neighboring Los Angeles County, the first California county to bring back indoor masking in response to delta. Not only were the hospitalization figures identical, but Orange County actually had a lower case rate.

Orange County has a similar vaccination rate to Los Angeles County (Los Angeles County's rate for the total population is 61%, just two percentage points lower than Orange County's), which makes it much easier to compare the two counties to one another than it is to compare Solano County to the other Bay Area counties