lynxlacelady wrote:

I think you are right. Bren and his contacts keep speaking of Machigi as the most dangerous man on the continent. His ability to think long term and act to benefit his people makes him a possible rival to Tabini. But in the last book Ilisidi says Tabini is the better aiji because his vision is wider and longer than Machigi. It will be interesting to see how this element in the story evolves.

Tabini's connections are all over the world and in space. Machigi's connection are in the Marid only. Tabini thinks about the world as whole because he's actually lived in both the east and west. We know he lived with his grandmother as a child and as the heir of the Aji, I'm sure he lived with many other people as a child. He has a firm grasp of history. Machigi's experience was all in the Marid. Machigi thinks in terms of his lifetime and maybe his successors lifetime. Tabini thinks in terms of centuries or more. 

I'm sure the east would prefer Tabini over any other potential western Aji.  
 

Personages and Aijiin are likewise built on the same motif.  Atevi are the distillation and ultimate expression of ideas/tropes that CJ explored in her previous books.