In my airline the calculations are made completely independently by the F/O and the Captain, on seperate Performace tools, with no discussion. Each individual sources the zero fuel weight figure independently, adds the fuel amount, adds a buffer for last minute changes and then at a time that suits the crew say " what did you get?" And a comparison is made. Once in a while the figures are a bit different because someone has not accounted for a wet runway or something similar and further probing ensues in order to determine who is correct. The system works well and the greatest weakness in it lies in the load control office where the zero fuel weight is calculated.
The second greatest weakness is in an individual's personal discipline, it is tempting to ask the gross weight used by the f/o, this should not be done.
I had assumed that after EK 407 that this was how most airlines did things. I would be very interested to know if I am wrong.
Interruptions and chatter on the flight deck during set up is also a threat and ground staff/ cabin members need to be disciplined in this area.