Some quick caveats, the employee count is for a year, and the UC system has about an 8% separation rate. The employee count also includes 29k student employees. Even so, that feels like way too many employees to service that student count, a bulk of which are listed as non-student professional and support staff.
Note that these employee counts probably include whole hospital staffs (since teaching hospitals / academic medical centers are frequently part of universities).
Yes, that is a good point. Staff employed by the hospitals are included. UC Davis alone is more than 10 thousand employees. I'd imagine a few of the other UC hospitals are also significant portions of that support staff.