First, a note from your humble webmistress: I really dislike Wonse. He was a disgrace to his profession, a coward, and mentally unstable. He's a very well-written character, but a horrible little man. That said, let us proceed with the file.
Wonse's entry in the Discworld Companion is as follows:
Former Secretary to Lord Vetinari. Wonse was one of life's subordinates, who rose from his childhood in the Shades. He was neat, and always gave the impression of just being completed. Even his hair was so smoothd-down and oiled that it looked as though it had been painted on. As the Supreme Grand Master of the Elicidated Bretheren of the Ebon Night, he was responsible for the summoning of a great dragon to try and usurp the Patrician. He achieved an accidental death while in Watch custody owing to the literal-mindedness of the then Lance-constable Carrot, who threw the book at him.
There is little that can be added to that eloquent description. Wonse tried to lead when he was a follower, and tried to outsmart the Patrician, which is clearly idiocy.