Nice work on the gear for both him and his horse (and he's riding like a Greek, not a Roman, cool!)
*snert* you're a glutton for punishment. I look forward to being educated about Hannibal - I know only the bare bones of his life.
Romans rode sitting quite far back on the horse, almost behind where the modern saddle sits, with legs extended forward (and no stirrups). Tellingly, one of their terms for a horse that trotted (rather than the comfortable pacing beasts they preferred - the ambulators) was cruciator. My understanding is that the Greeks sat a bit further forward, legs not quite so extended. Most of the folk in Europe and Arabia who were descended from the nomadic warrior tribes of the Asian steppes (and this would include the Celts) appear to have ridden with a position fairly close to the modern seat. Saddles were made of stuffed pads until about the beginning of the Christian era, when saddles with wooden frames came in, and stirrups were even later. In general, the more your cavalry fighting style depended on rapid evasive action, the more likely you were to ride with bent legs, seated forward; it's just more secure. Not sure about the Iberians of the time or the Africans: you probably know a lot more about the ethnic mix of Carthage and their battle tactics than I do!