Arrian on Alexander's administrative measures
Plutarch of Chaeronea is quite certain that Alexander was in trouble when he returned from India.
The difficulties of Alexander's march into the upper country, the wound he had received among the Mallians, and the losses suffered by his army, which were said to be considerable, made men doubt his safety and encouraged the subject peoples to revolt. The generals and satraps were incited to commit many injustices, exactions and actions of violence; in short, restlessness and a desire for change spread everywhere.note[Plutarch of Chaeronea, Life of Alexander 68.3.]
In December 325, Alexander had several officials executed. It will never be known whether the satraps had behaved badly; it is also possible that Alexander tried to get rid of people he did not trust. The Greek author Arrian of Nicomedia, describes Alexander's measures in section 6.27.3-5 of his Anabasis. The translation was made by M.M. Austin.
[6.27.3] When Alexander had reached Carmania, Craterus arrived bringing with him the rest of the army and the elephants, and also Ordanes, who had revolted and started a rebellion but whom he had arrested. There also came Stasanor the satrap of Aria and the satrap of the Drangians, and with them Pharismanes son of Phrataphernes, satrap of Parthia and Hyrcania. There arrived also the commanders who had been left behind with Parmenion in charge of the army in Media, Oleander, Sitalces and Heracon, bringing with them the largest part of this army.
[6.27.4] Both the natives and the army itself made many accusations against Oleander and Sitalces, charging them with plundering temples, rifling ancient tombs, and other unjust and arrogant actions towards their subjects. When this was reported, Alexander put these two to death, to inspire fear in all the other satraps, hyparchs or nomarchs who were left, that they would suffer the same fate as these if guilty of misconduct.
[6.27.5] This more than anything else kept in order the peoples who had been conquered by Alexander or who had come over to his side, though they were so many in number and so far apart - that in Alexander's kingdom the subjects were not to be wronged by their rulers As for Heracon, he was for the time being acquitted of the charge, but not long after he was convicted by men from Susa of having plundered the sanctuary at Susa, and he too was punished.