The Mauryan theory is probably the main theory about getting a China-like Indian subcontinent, yet it needs some help/ stable support for it to work.
Though one reason I believe the Indian subcontinent wasn't able to unite full and form a permanent single state is the fact religion is so deeply grounded there. For most of China's imperial history Confucianism and Legalist philosophies, which to the extent of my knowledge discouraged or didn't mention deities. From what I've researched animism, and ancestor worship was where it was at (animism res-urging in the Warring States, Three Kingdom and other periods of fragmentation).
To the Chinese they were 'All-Under-The-Heaven', the Heavens and nature mandating the Celestial Emperor, quite possibly the closest thing they had to a proper deity. From a serf's point of view, who could challenge the Heaven's orders and rebel against the Emperor? And when time did come it would hit hard through extreme decadence in the Imperial court so people were definite that now was time to rebel as the dynasty was out of favor with the Heavens.
In the Indias, the closest thing you get are the Nastika schools which Jainism and Buddhism stemmed out of. Buddhism was very soft core Nastika philosophy and Jainism asked for extremities form the householder that not all could complete so it gained a substantial community, though it remained a large minority for a long time. Neither actually denounce gods, goddesses and spirits.
What you need to is to get a Nastika school which is deist to say the least. And such a school is the Carvaka thought. It actually goes insults the Vedic religion and their Brahman priesthood at many points in it's scriptures and denounces that anyone but a king or a scholar should be able to communicate and herald for God.
Get a Carvaka school student (or one of a similar thought structure) to curry favour with the Mauryan or Sungan empires. Heck you could get it to work even with the Nanda empire in the face of Alexander's invasion or the Kushan empire!