In one playthrough, the Olmecs had overwhelming influence on every territory.  It took a little play with the interface to figure out how to see where this was coming from.  Was it attenuated by distance?  Did roads or technologies help it carry more effectively.  

It was also unclear what advantage this gave, though it did allow the Olmecs to demand more territory.  Is this influence intended to represent cultural dominance?  If so, it would seem that cities with more cultural buildings should have some defense against this.  The current mechanic may be fine in practice, it just needs to be better represented in the interface.