Dorian proved that he knew what he was doing even when he was Captain of the Hunters. His actions probably did nothing more than stabilize the clan; but at that time, it was probably what was needed most. Have to wonder if some of those that left the merged clan, or even those that stayed but lost status would not be the most likely behind the assassination.
In the present, watching the death of the former council President, would have been terrifying. The death, while relatively painless, would have been unbelievable for those seeing it in person.