Master Slave Trolley Arangements?

[technomage]

The topic of Master/Slave Trolley Arrangements have popped up on Ger21's Thread on a replacement for round rails, so I started a new thread to see what people think about Master/Slave Setups. I have started with 8 rough examples of typical setups labeled A,B,C,D,E,F and G.
To make things a little more focused lets say a cutting area of 60" x 34" for this discussion.
Also lets say that the rails are 1 5/8" Strut material.
http://www.b-line.com/pdf/catalogs/P...B22Channel.pdf
12 Gauge B22 Product
so the engineering data is available for deflection etc for the megabrains in the group.
Okay thats the playing field lets talk Master/Slave and why?
feel free to add any arrangements I missed.
Interested in any feedback.

Ps. Personal arrangements with others should go to Dr Phil's Forum.