Cleitus.

This is coolbert:

"Our enemies are Medes and Persians, men who for centuries have lived soft and luxurious lives; we of Macedon for generations past have been trained in the hard school of danger and war. Above all, we are free men, and they [Persians] are slaves. There are Greek troops, to be sure, in Persian service — but how different is their cause from ours! They will be fighting for pay — and not much of it at that; we, on the contrary, shall fight for Greece, and our hearts will be in it. As for our foreign troops — Thracians, Paeonians, Illyrians, Agrianes — they are the best and stoutest soldiers in Europe, and they will find as their opponents the slackest and softest of the tribes of Asia. And what, finally, of the two men in supreme command? You have Alexander, they — Darius!"  – Alexander the Great (c. 335 BCE).

THEY WILL BE FIGHTING FOR PAY! GREEK MERCENARY TROOPS IN THE SERVICE OF THE PERSIAN. 

From the wiki: "The death of Cleitus"

Black Cleitus!! That most esteemed soldier in the Macedonian army and personal confidant of both Philip of Macedon and Alexander the Great!

Cleitus when told by Alexander that he was going to receive a command of second-rate soldiers, " he spoke his mind". Second-rate soldiers as those Greek mercenaries having previously fought for the Persian Darius the idea of commanding such troops not acceptable to Cleitus.

REMARKS BY CLEITUS AS DIRECTED AT ALEXANDER THOUGHT TO BE SO PROVOKING, CLEITUS KILLED ON THE SPOT!!

coolbert.