Hi Alex,
The MoGraph calculations are typically done before the Dynamics. Per Frame. The next frame needs to implement things MoGraph is supposed to supply to the clones. Since it can’t just ignore the dynamics, it needs to know the last state of the clones. From there it adds everything that would have happen without the dynamics even. Then comes the next dynamic calculation. The next frame starts that all over again.
So, which cache to use? As usual, it depents. MoGraph Cache holds all needed information from MoGraph of course, and as the manual states, some parts should not cached otherwise. Dynamics excludes most MoGraph data, but contains collision data for example, if needed. To get more used to it, set up a simple scene, a sphere and a floor, and experiment with it. To start with complex scenes and run into problems will wear one down, and that is not fun. Small scenes are fast and most of the time much clearer.
https://help.maxon.net/us/#TMOGRAPH_CACHE
https://help.maxon.net/us/#DYNRIGIDBODYTAG-RIGID_BODY_GROUP_CACHE
https://help.maxon.net/us/#DYNWORLDOBJECT-WORLD_GROUP_CACHE
In the file above, the offset is progessively animated. Practically, this is like being in a train and walking in the opposite direction. The impression will be, that the movement will be lower, e.g., if the train moves as fast as the walker, the surrounding will not change/progress. Yes, to see that in a simple slider might be kind of abstract, but I hope it helps.
All the best