It would be too long a story to mention all the other absurdities of his narrative, and it will suffice to point out a few.
He tells us that Alexander in drawing up his army was most anxious to be opposed to Darius in person, and that Darius also at first entertained the same wish, but afterwards changed his mind.
But he tells us absolutely nothing as to how they intimated to each other at what point in their own line they were stationed, or where Darius finally went on changing his position.
And how, we ask, did a phalanx of heavy-armed men manage to mount the bank of the river which was steep and overgrown with brambles?
This, too, is inexplicable. Such an absurdity cannot be attributed to Alexander, as it is universally acknowledged that from his childhood he was well versed and trained in the art of war.
We should rather attribute it to the writer, who is so ignorant as to be unable to distinguish the possible from the impossible in such matters.
Let this suffice for Ephorus and Callisthenes.
Walbank Commentary