On a widebody with a reasonable amount of airframe hours and a decent passenger load, I’d be surprised if the *actual* weight of the aircraft was within a couple of tons either way of what you thought it was.
and you are a widebody driver?
Well IMHO it depends WHY is TOW limited. Structural? Performance? Landing weight?
You dont know why the performance people have calculated this, Did you think of what was taken into account? Their PROFESSION is to optimize the flight, your PROFESSION should NEVER second guess them.