It is odd that they need so many staff. How on earth does Anne manage given she does more engagements?
Because Anne’s work is handled by the Buckingham Palace team for all the “pay and rations” stuff. She will clearly have assistants (likely a Private Secretary and Assistant PS and an admin strati e assistant or possibly two) to deal with organising her commitments/diary/travel arrangements/correspondence etc but Anne herself is not dealing with their payroll, expenses, HR needs, nor her own communication needs or social media. All of that gets picked up by the Buckingham Palace team.
The Wales have their own household, so they need to also do all that work for their staff. Plus finance, IT, operations - all that “stuff” that needs to be done and takes a surprisingly large number of people to manage for an organisation of any size.
(Our household are big fans of Only Connect too)