From what I understand, it was Xanthippus of Sparta that the Carthaginians hired in the First Punic War to train them in the art of proper Open plain warfare. The Carthaginians often avoided fighting the Romans in the open because the Roman manipular system was absolutely devastating to them. He apparently created the basic Carthaginian battle line (with elephants, cavalry, and the Phalanx) and trained a good number of troops in the Greek style of Phalanx warfare.
I'm not sure if the Carthaginians had the Phalanx going for them before this, but its apparent that Xanthippus did a great job in teaching them. But the tactics and phalanx he taught them was the Greek style phalanx .. A Phalanx, as mentioned, is not about the type of weapon you have, but the formation the troops are in. Phalanx could be Hoplite, or Pike armed.
Basically, Hannibal's veterans probably ended up looking very much like Triarii as they had plenty of chances to loot the battle fields in Roman territory. They probably entered Italy with gear and the style of Libyan / Greek hoplites and left it looking more like Triarii after discarding worn out gear and picking up Roman equipment.