Torquing to a known torque and painting marks is fine...except there's no guarantee the clamp load hasn't changed due to all the mating surfaces wearing.
There's also too many variables in the real world if the application is critical enough. Clamp load changes with how many times the fasteners have been assembled due to the threads getting polished, how clean and dry the fasteners are, etc.
There's also too many variables in the real world if the application is critical enough. Clamp load changes with how many times the fasteners have been assembled due to the threads getting polished, how clean and dry the fasteners are, etc.