considers a number of 10,000 cavalry to be more likely, but he doesn't mention the figure of Diodorus. Arrian's claim on the strength and composition of the Persian infantry has elicited more detailed discussion. There have been arguments that the figure of 20,000 is accurate, but also included non-Greek native infantry. Others have argued that Greek mercenaries may have been the only infantry present but were not as numerous. Krzysztof Nawotka considers Arrian's claim of 20,000 infantry credible, but does not think it consisted entirely of Greek mercenaries. Such a large force of mercenaries would have been raised only very occasionally, after a long period of preparation and under the command of the Great King. Because the Achaemenids had not made such preparations for the battle, he judges that only a small fraction of the infantry were Greek mercenaries. Accordingly, local detachments of little military value made up the vast majority of the infantry. Based on Plutarch's statement that the infantry of both sides engaged after the Macedonian phalanx crossed the river, Ernst Badian likewise believes that non-Greek infantry was part of the Persian army and posted directly behind the cavalry. In this light, he considers 20,000 as an reasonable estimate for the total number of infantry. He believes that Arrian's claim that all Persian infantry consisted of Greek mercenaries was either a mistake or an attempt to enhance Alexander's glory. A.M. Devine argues that Arrian likely exaggerated the number of Greek mercenaries for propaganda purposes. He notes that the only other information on Greek mercenaries in Asia Minor at that time is given by Diodorus and Polyaenus. Diodorus writes that Memnon's force of Greek mercenaries, which Darius III had sent to Asia Minor to fight the Macedonian expeditionary force, numbered 5,000 men. Polyaenus gives a lower number for these, 4,000. Assuming that Arrian was right in his claim that the infantry consisted exclusively of Greek mercenaries and that the figure of 10,000 cavalry given by Diodorus is plausible, he suggests that the Persian army likely numbered 14,000 to 15,000 men. This was significantly inferior both in numbers and quality compared to the 18,100 men fielded by Alexander. Like A. M. Devine, J. F. C. Fuller thinks the number of 5,000 mercenaries given by Diodorus is more realistic, but he thinks there must have also been a considerable force of local levies. A.M. Devine goes on to argue that this