Some general thoughts...
It's way too hard to eliminate members of an entourage who have come to dislike or suspect you; and this is a problem, because currently the only way to permanently get rid of evidence (and the easiest way to calm your population) is to dump it onto a member of your entourage who likes you and then make them a scapegoat. Once you have an entourage member who knows you're dark, there doesn't seem to be any non-supernatural way to get rid of them.
Currently the only way to get rid of an entourage member who dislikes you is to kill them with dark powers, which is too expensive to contemplate most of the time and unrealistic.
There should probably be options to use conventional assassination (at no Power cost, but at the risk of creating evidence), plus the option to dismiss entourage members (at the risk of them sending messages to everyone with warnings and all the information they gathered, plus potentially raising the suspicion of other members of your entourage and even your peers depending on the situation.) Having a Baron replace their Captain of the Guard shouldn't require some complicated frame-up or an invocation of dark powers.