Originally Posted by
randy_cat
Dunno exactly, but since they were so effective in Alex's campaign, it is likely agrianians became a part of the makedonian army later when Alex died. Peltenai fulfill the same role ok, yet they are not exactly the same unit. Maybe there is room for another unit of picked light infantry that serves under makedonian rulers, something between peltenai and makedonian peltastai in terms of strength. There's also hellenized Thracian infantry that serves as middle ground between these (Katoikoi Thraikes).
As for the cavalry, we know Hannibal brought with him the numidian horsemen, who fought with just javelins and maybe sword and shield but it is unlikey they routed the roman cavalry by themselves even if romans were kind of weak horsemen. So there was some sort of medium/heavy cavalry that broke the roman's left wing and allowed Hannibal to flank and surround the romans. If they were numidians or iberians that re-equipped themselves with looted gear, or they already had their own panoply, i don't know for sure. There could be room for some sort of iberian/african heavy cavalry who supported cathaginian armies, like in EB1.