I'd like to see JW's put in their place too SBF !
I agree, a diagram like that goes straight in to the mind, wheras as a fact is heard, or read, the defensive argument is forming in the mind. Even though that argument comes fairly quickly when looking at the diagram, it comes with doubts, "why did they show Russell springing from the 2nd Adventists ?" (or whatever the diagram shows) and the JW may well begin to reasearch for himself.
A picture says a thousand words.