W&B varies based on the load, operational requirements, and conditions at departure. An international widebody shouldn't usually have problems as the ground crew should already have a plan of what sequence and where freight cargo should be loaded. If a balance issue was found after pushback it's most likely related to how some of the weight/load data isn't complete until the flight is closed.

On some of our flights with ACARS, the crew can input thefuel load, # of pax and their bags (by zone or bag bay: x# zone 1, y# zone 2; a# aft bag, b# fwd bag), and send the data out and get a takeoff data for the current conditions which included the stab trim setting for W&B (certain range required for takeoff).

Environmental conditions can restrict weight which can require removing pax/bags due to WX (hot at departure location), or extra fuel needs to be carried for possible holding or diversions due to WX at destination.