Total staff numbers are only marginally useful without further breakdown, as that article points out.

A family member works for an eatery at a large university. Technically they are employees (staff) of the university, but pretty much in name only. They work for a business unit which receives no financial support from the university. They are profitable on their own and if they aren’t, they would close down. They are provided benefits via the university, but it is part of their budget. Including them in the count relative to students is about as useful as including the employees of the (independent) Starbucks on campus.

(It’s not Stanford, so I can’t speak to that specific institution)