No.. it can't be.

[Tellos Athenaios]

I'm just curius, what was the composition of your 2830-men army? I guess you didn't have enough Thureophoroi or peltasts (to win the wall battle) and archers/slingers to kill the elephants from the safety of the walls.

Reconsider that statement when looking at the actual army composition of those Indos valley cities.... By the time those cities have sorted their recruitment out, then those armies are worthy of a human player. Actually it is one of the few areas where the slave AI does recruit some pretty nasty armies, armies I could've thought of myself for a highly effective campaign army.