Judging by the type of movement (which seems to be "Floaty" or "Subtle) - > 3 Things that might be causing it:
1) Mismatching FPS between your AE Comp and your C4D File.
2) Mismatching Interpretation of your Rendered Footage FPS in AE.
3) Your external compositing tag is placed on the Negative Z Axis side of the 3d Screen rather than the Positive Z axis. (for ex: X: 0 Y:0 Z: -100 instead of 100 or vice versa)
and a Bonus possibility:
4) You've unintentionally dragged that wacom while having it pressed on that Ex tag layer