Final drive, double planet gear system

The final drive of the komatsu PC300-3 and other dash 3 excavator is equipped with a double planet gear sytem. I remember there was three marks on planet gear and on sun gear. These marks should be used to asssemble the final drive. On the other hand, the same design is used for the swing machinery but without any marks. Anybody have the answer for this?

Final drive, double planet gear system