Though I agree the culture limit is an issue, fact remains that the Mauryan Empire was until its collapse a major actor in that area of the map, that successfully kept the Seleukids at bay (or even conquered some former Seleukid lands), played an important political, economical and military role.

I understand the difficulties to represent it correctly, given that most of the Empire would be outside of the map. There's also - I think - a lack of sources when it comes to the military aspect of the Empire (the only thing I could find Megasthenes' '600.000 infantry, 30.000 cavalry and 9.000 elephants').
What I mean is simply that the Mauryan Empire was for quite some time a power that was feared by the Seleukids (who were arguably the biggest military power of the hellenistic world), that deeply influenced the cultural and economical life in the area, that is partly responsible for the spreading of Bouddhism and what not. Whether a Mauryan/Mauryan satrapy faction appears in game or not, something should be done to simulate Mauryan foreign policies toward the Seleukids, Bactria and the Saka (rebels stacks spawning whenever the player conquer indian provinces or something like that would be a first step).