Smoking a London Broil (Top Round)

I picked up two because they were on sale for buy on get one free. I know the history about it essentially being a cooking method and not an actual cut, but nonetheless thats what it is labeled.

I was planning on smoking it and was wandering if anyone has any experience or advice with it?

Number two i know it is a tough cut and everything I have read says cook to medium at most. Why cook to medium on this cut and the brisket, another tough cut is cooked to 200 degrees. Is the fat content of a brisket that makes the difference?