My auto-attack on a training dummy seemed very high (14%). In looking through the log, there was a great disparity between hits. Each of the large hits was exactly the same as a Rot Flesh double attack, so it appears that the normal hit of the Rot Flesh DOT portion is being written to the log as just disease damage. Also, they are added together because I have a disease infusion on my weapon and using the Thaumaturge ascension class.