Well I'm no scientist either, but I did stay at a Holiday Inn Express last night.
I often put a pork butt above a brisket in my cooker and allow the rendering pork fat to baste the brisket, but I have never put a brisket above a pork butt to allow the beef fat to drip down on the pork. Not sure why, but it just seems wrong.
Mister Bob, Pitmaster - Bob's Hogs. KCBS CBJ #31759 - IMBAS Certified MOINK Baller