Ernst, I must have missed something in the Jaimini III, Class II regarding the dasas. You refer to one class study chart as the Pisces/Leo Dasas time period in their life as when the person divorced. Where do you find the Dasas time period given by the rasi? Is one to use the Vimshottari table to discern the rasi period from lordship of graha offered there or do I use another table for this?
Never mind, I have answered my own question by going back over the lesson I finally heard your reference to the Chara dasa. Only question left is, what is the difference in these Dasa's using rasi rather than graha?
The difference is in that they are based on motion of time through rasis instead of through nakshatras which the Vimshottari dasa is based on. Rasis are the concrete reality, and so these dasas reveal the concrete. Nakshatras are our reaction to this reality and how we try to live in the reality, which is usually in conformation with the event and so they work for predicting events as well.