Comment by rurban

Easy to explain. The USSR was a simplex system, the Roman empire a complex system.

he mostly explained large vs small systems, and didn't really qualify complex systems, until the very end.

a better explanation would be military vs democratic systems, the military being the simplex one, with straight hierarchies. the democracy with various complex interlinks, feedback loops and control mechanisms. Military is like a company, need to grow fast, and dies fast. commands need to spread fast.