The circuit assembly 'shortfall' is an utter scam.
The congregations of the circuit donate and donate until there is enough money to buy or build a circuit hall. The title of the new hall is held by the society.
The society then charges the circuit congregations a 'per head' fee for using the damned hall they already paid for.
So for example, if a circuit section made up of 10 congregations has 1000 publishers between them, the society will charge maybe £3 per head for the assembly, this means the circuit will start with a deficit of £3000.
The elders of the circuit have a meeting at lunchtime and 'agree' the suggessted donation to the society, so the circuit funds are hardly ever in 'surplus', I've known a surplus announced about once in my years attending.
I did wonder, even as a faithful dub, how one day's use of the hall could require £3k in electric bills, cleaning supplies and toilet paper.