And the reason for the feint in the one paragraph. Unfortunately, the muddled transmission of the battle and the conflicting source traditions do not make for confident reconstructions.

Arrian is not at all at his “best” here. It is certain that two sources are being followed (Kallisthenes and either Aristobulos or Ptolemy). This likely leads to the double mention of Krateros’ taxis (centre and left of line). It also underlies (Kallisthenes) the downplaying of Parmenion as opposed to the dashing king.

Meanwhile, the remainder of Alexander’s right wing–the Agrianian javelin men, Cretan archers, two phalanxes of shield bearers and three right phalanxes of Foot Companions–also advanced…

Arrian only states that Alexander ordered “Amyntas, son of Arrhabaeus, to make the first rush into the river at the head of the skirmishing cavalry, the Paeonians, and one regiment (“taxis”) of infantry…. Arrian uses taxis as a utility word; it can describe anything from a unit to a battalion. The assumption is that a chiliarchy of hypaspists is meant but that would necessitate Alexander removing a chiliarchy from the left of the Companion Cavalry creating a gap in the all important link between infantry and heavy cavalry. It would also mean that a third of the king’s guard troop was detached from his strike force.

If any troops are indicated it would be the Agrianes. These troops, from their placement in other battles, clearly performed the role of hamippoi. It is likely they did so here as well. The hypaspists, as was their remit, will have crossed the river with their king.