Having one slip off drum and one staked drum should not cause problems. It just means one drum comes off more easily for a brake inspection. As long as the thicknesses of the drum faces are the same, it wont cause any tracking/alignment problems either.
A finned drum and a smooth drum could cause a brake pull when warmed up... not unlike using a drum near max diameter and a new drum. One side wouldn't cool as well and could effect braking.
