I doubt they'd be able to remove levels from striking dummies without making them near useless. If it was that simple, MMORPGs would already be doing it so they don't have to keep changing their striking dummies every time they increase player level cap.

Suggest that your FC hide the "unattractive" striking dummy (aren't they all in the long run?) inside other items that fit the decor better instead. The item combinations thread has some examples of how FCs have hidden their striking dummies.