Auto firing skills are relatively easy to get back up through leveling. Of all of the BattleRager skills, DB would be the one I would think is LEAST likely to be a pain in the ass to get back up.

...and yes, I think skill reductions, imm xp removal, setting diseases on characters, etc - are all fine ways to strongly encourage cabal members to act within their role. Compared to the alternatives (titles, cabal removal, etc).

It's a less public way of getting the player's attention.