My question comes from this detail in the wikipedia article on the Seleucid-Mauryan War:
(...)
The region fell to the Mauryans; and Chandragupta also took over the Kashmir and the Hindu Kush. At the same time, Chandragupta expanded into the Deccan. Chandragupta took over the Punjab also, and by 303 BC he had taken over Eastern Afghanistan and everything in between.
Since wartime communication must have been quite limited in that era, how did the commanders coordinate campaigns that were nearly 2000 km distant from each other? Was there a high level of delegation? Did Chanakya lead the operations?
I would also appreciate some recommendations and sources on the Seleucid–Mauryan war.
There is no evidence that Chandragupta Maurya ever expanded into the Deccan in the first place. As far as I am aware, there is not a single source that mentions this. Admittedly, our sources for this period of history are extremely sparse, but going off the evidence we have available, it seems that the Mauryas had no presence in the Deccan until the time of Ashoka. It was under Ashoka that we find Mauryan inscriptions in the Deccan (though we should be careful in extrapolating Mauryan political domination from these epigraphic records), and it was under Ashoka that Kalinga on the eastern seaboard was conquered by the Mauryas. Kalinga is located immediately south of the Mauryan capital region of Magadha, and lies astride the most important route connecting Magadha with the Deccan; thus, if even Kalinga was not conquered until the time of Ashoka, then it is highly unlikely that lands located even farther south and further removed from Magadha could have been overrun by Ashoka's ancestors.