Vicky: now I see your question, but I didn't do that on purpose, reason is it could produce different result because of rounding errors, for all other places it's division first and then addition/subtraction.
Continuing discussion on Discord:
David: re: rounding errors, in general, addition & subtraction before division would yield less rounding errors
Vicky: But it will produce different errors, and easily it will create authorizedOverall different to sum of authorized
From GH (https://github.com/nucypher/nucypher-contracts/pull/254#discussion_r1587594690):
Continuing discussion on Discord: