Having completed the Third Macedonian War, which was a brutal exercise, what was revealed there has thrown light on some of the unexplained numbers from the Third Samnite War. One in particular relates to Plutarch's claims (Life of Pyrrhus 21 8) that at Asculum in 279 BC, Pyrrhus had 3,505 men killed, information Hieronymus of Cardia claims, were gleamed from Pyrrhus' commentaries. Because, for years, I could not find a Roman connection, I had accepted it as genuine, that is the source was taken from Pyrrhus' commentaries. This now has changed.
The 3,505 men killed has been rounded from 3,504 men. It's a recycled number and it's the same troops mentioned by Dionysius' account of Asculum relating to the body of Daunians, from the city of Argyrippa, consisting of 4,000 infantry and "some" 400 cavalry that were sent to the assistance of the consuls. These troops went on to attack Pyrrhus' camp for booty. Some of these troops may originally been levied from Argyrippa, so there could be some truth in that, but they all come from the Roman camp, with the intention of attacking Pyrrhus' army in the rear. Because of a lack of discipline, this force went and attacked Pyrrhus' camp for booty, something the Romans have covered up. From the camp guards, those troops with the most campaigns under their belt, or the better experienced troops are sent out as an emergency reserve, as happened at Beneventum, when again fighting Pyrrhus. Those with the lowest campaigns served, remained behind to protect the camp. Someone has taken the reserve force, and removed the equivalent of a campaign division so as to arrive at 3,504 men.
This brings into question the legitimacy that Hieronymus of Cardia obtained these figures from Pyrrhus' commentaries. According to Diodorus (between 60 BC and 30 BC), Philinus of Acragas, who lived and wrote during the First Punic War, claimed that the Carthaginians army, under the command of Hanno, sent 50,000 Carthaginian infantry, 6,000 cavalry and 60 elephants to Agrigentum. This easily breaks down into numbers derived from the Romans and their allies. I'm starting to believe these ancient authors pretend to use sources so as to give them credibility, or they have been duped.
So, what has this got to do with Greek military organisation? After breaking down all the Roman units into the number of men belonging to a particular campaign division, this reveals that the foundation of Rome's military organisation has been built on Greek military organisation (lochos, pentekostys, enomatiiai etc). Only now have a seen this, and after going back and thoroughly examining everything, it's all categorical.
In relation to Arrian's expedition against the Alani, it confirms that Arrian, like the Pyrrhus example, has left behind those troops with the least campaign experiences. This might explain why Arrian went "Greek" with his organisation descriptions, because he is left with the Greek military organisation.