The nature of a ramp in a new factory is that it's more important to get all the ducks lined up before pressing the "high speed" button than it is to force as many cars out the door ASAP. It will start in fits and spurts with more emphasis on testing and tuning before the emphasis turns to volume. The cost per car goes way down when the production line is properly setup and tuned. All of this needs to happen in coordination with the supply chain. Until then it's not desirable to make a lot of cars and the pressure is focused on continuing to improve the line. At some point soon we will likely see production rates take a big leap forward and then the focus will be on keeping production high while continuing to fine tune and improve the line (the optimization and fine-tuning never stops).
Of course, the sooner we get to that step-change in volumes, the better. I can see how the German engineering culture, when compared to the Chinese "get 'er done culture", would likely have a longer time to hitting the "high speed switch" but have a faster ramp from that point and it makes sense that the China ramp would be smoother, with more early production that grows more gradually (but still very impressively). The German production will have a higher degree of automation which takes longer to setup but that will likely be able to hit higher rates eventually.