The numbers get even muddier because some of these companies have national holdings, and the SF Chronicle mixes large national numbers with smaller regional numbers for effect.
The study itself is interesting for how they attempt to algorithmically link property titles with beneficial [corporate] owners, but it seems they felt they needed to juice things up with rhetoric and innuendo to actually sell it. I cancelled my SF Chronicle subscription awhile ago as the paper is hardly any better than FOX News. They really work hard to stick to their narratives, which is a real shame as it's the newspaper of record in SF. (The odd thing is that the comments section to every article almost reads like an actual comments thread from foxnews.com. That is, most of the people engaged enough to comment seem to be at the polar opposite of the political spectrum. Which makes every article doubly useless--the journalists and the commenters lobbing endless non-sequiturs --and also raises some fascinating questions about to whom is the paper actually trying to appeal, etc.)