The author's usage of the word "Celtiberian" in the first book is wrong, as he uses it to cover Lusitanians, Carpetanians and any Hispanic tribe that is not Iberian. Actually, none of those tribes were Celtiberians: Carpetanians were just Celts (albeit they did speak a variation of Celtiberian language, enough to be sometimes classified as such) while Lusitanians were a Celtized Indo-European group (whose ancestral language was significantly different from Celtic). This is somewhat corrected in the second and third books.
As said in the book, the Iberian Oretani tribe did sport some important Celtic influences, including the god Endovelicus and the famous torque collar. However, the author once describes the Oretani owner of a dirty, cheap inn wearing a torque (and a silver one to boot), which would be completely out of place on someone with such a lowly occupation given that torques were only worn by chiefs and very powerful people.
The trilogy's character names range from perfectly believable to completely wrong for the time and place. Among the latter we have Mádriz (a corrupted form of Madrid, a medieval Muslim city name), Iñurbe (a vaguely late Basque-sounding name that contains the letter Ñ, which was introduced in the Middle Ages) and Dimitri (a Russian form of the Greek name Demetrius).
The author seems to be unsure of what language he wants to use for the character names. Regardless of their nationality, some of them are rendered in their Greek forms (Botilkos, Sosylos) and others are modern Spanish renditions (Aníbal, Orisón), and some Punic names are kept in un-Latinized Phoenician (Kharbaal, Saphanbaal) while others aren't (Sofonisba, which is the same as Saphanbaal, by the way).
The idea of a Celtiberian like Kaukirino calling Iberian women "indecent and unmodest" seems arbitrary, if not potentially the exact opposite of reality. Historically, Celts were described as quite liberated in comparison to the more conservative Greeks and Semites; they lacked the classical Hellenic taboos about passive sexuality, for instance, and had their women occupying significant roles of power (warriors, judges and even queens) with some frequency. Considering that Celtiberians were eminently Celtic whereas Iberians were greatly influenced by Greek and Phoenician culture, odds are that a Celtiberian in real life would have opined that southern women were too prudish.
For some undiscernible reason, Istolatius's Celtici warriors are described exactly like Gauls: they use wild frontal charges, carry shields as tall as a man, wield longswords, and sport blond hair and long moustaches, all of which would be an excellent description of an Alpine Gaul army. Needlessly to say, things like longswords and that kind of hair were relatively alien to Hispania and absolutely to a southern tribe like the Celtici.
Military
While Hamilcar could have believably had Greek mercenaries in his army when he invaded Hispania, those surely weren't a significant portion of his army, given that no chronicle mentions them, and the probability that they were specifically a large contingent of Spartans, as portrayed in the book, would have been almost unrealizable. Historically, the Spartan national army was always quite small when not counting allies and vassals, and even the greatest battles of their history often see numbers like 10,000 at the very maximum; in order to gather the several thousands seen in the book, Hamilcar would have likely needed to borrow half of the entire Spartan army from Leonidas II and Eudamidas III at the time.
The text uses the term "hoplite" for all kinds of heavy infantry featured in the battles. Historically, hoplites were not any kind of armored soldier, but only those characterized by carrying spears and the huge, round hoplon shield. Moreiver, although Carthage seemingly did use hoplite-like fighters in the old times, possibly up to the time of Hamilcar, most experts believe they had been phased out by the time of the Second Punic War. Ancient sources imply that Hannibal's Lybian heavy infantry resembled their Roman equivalent in equipment and mobility, and considering that Romans had long ago abandoned the hoplitic style in favor of oval shields, more flexible formations and swords over spears, it's probable Carthage had done the same.
In the line of the previous, the second book has Hasdrubal Barca arriving to Castulo with a Macedonian-style Hellenistic phalanx, sarissas and all. Macedonian influences were strong in Hannibal and his family, but the idea that the Barcas used that formation at the time is unlikely given how sources describe their movements and battles. There is even controversy about whether the Carthaginian army, Barcid or not, ever used the Macedonian phalanx at all.
The historical Sacred Band of Carthage, which appears in all three books as a sort of military police in Carthage, was disbanded during the Sicilian Wars, almost a century before the trilogy's events. Carthage continued using citizen forces as commanders and elite guards, but they never went under that name again.
The trilogy has virtually all the Spanish tribes using falcatas, which is a popular mistake in the vein of Every Japanese Sword is a Katana. It's particularly bad when speaking about the Celtiberians, as they were known for favoring straight swords that were adopted by the Romans as their famous gladius. The novels don't even leave open the possibility that their usage of falcatas could be an individual preference, as there is no mention or any other kind of sword in Hispania (except longswords, which should not have been there at all, and a brief mention of Lusitanians using accurate antennae swords). In fact, when the characters later bring up the concept of a cutting/piercing sword in the vein of the Celtiberian item, it is explained as if it was some kind of quaint new model invented abroad.
In a related point, falcatas were tailor-made for every warriors, not mass-produced as shown by the Saguntum blacksmiths in the third book.
Characters
In the books, Hamilcar Barca intends to make Punics and Spaniards intermingle in order to create a "superior race", something vaguely similar to Alexander the Great's dream to mix the Greek and Persian races and cultures. In real life, some members of the Barca clan did marry Spanish women for political reasons, but judging by historical chronicles of his actions and policies in Hispania, Hamilcar never deliberately attempted a large scale inter-breeding program as Alexander did - or if he did, it had little success, given that Punic colonists were still ethnically recognized as such a century later.
Hannibal is portrayed as more resentful and petty than historical sources suggest (and let's not forget most of our sources are Roman, so they probably don't portray him objectively either). A notable example happens in the siege of Salmantica: where the real Hannibal saw its population as a Worthy Opponent whom he eventually let free for their bravery and ingenuity, the literary Hannibal is only enraged at them and it takes Hasdrubal to convince him not to order to butcher everybody.
Hasdrubal the Fair's blood family remains unknown, but it was probably not Gisco as told in the books, as those were rivals to the Barcas. The fact that he gets called Hasdrubal Gisco several times seems to imply he is being combined somehow with the real Hasdrubal Gisco, a general of the late Second Punic War.
In this story, presumibly for Rule of Drama, Himilce is the daughter of the chieftain Orissus. In real life, Himilce's father was another chieftain named Mucrus, and nothing indicates she and Orissus were closely related in any way other than both being Oretani aristocrats.
Gaia of Numidia is introduced as a lowly warlord who wishes his son Masinissa to be king someday. In real life, Gaia was already king of the Massyli.
