The painting_(artwork) tag is constantly misunderstood and misapplied, it's regularly tagged on digitally created images, as well as some posts featuring "a painting" (painting_(object)).
The posts under painting_(artwork)should be updated to traditional_painting_(artwork), and any leftover digital paintings should be retagged. painting_(artwork) should at least be disambiguated, but is probably better off re-categorized under Invalid.
I don't know if this can be done in a single BUR, but (I think) the steps would be:
update painting_(artwork) -> traditional_painting_(artwork)
imply traditional_painting_(artwork) -> traditional_media_(artwork)
category painting_(artwork) -> invalid
Updated