I'm not sure if your premise that a Celestial is less complicated than a perpetual is true? While it is a fact that a Perpetual has a lot more dials, this may NOT be the only measure of complexity. Indeed, the 5078 only displays Hours, Minutes and Seconds but no one would deny that a Minute Repeater is a Grand Complication. In this case both the 5140 and 6102 share the same base 240 movement. The Perpetual movement has 275 Parts, however, compared to 315 for the Celestial.