Polybius speaks little about Hannibal's manner of departure.
Livy states that the soldiers that were considered unfit for service; were distributed to garrison duty in a few Bruttian towns.
He did probably already have a port and access to ships
Livy implies that these were the same soldiers that fought in Trebia, Trasimene, and Cannae.
Perhaps some of the African veterans were in the second line, along with the militia. Livy states that there was also one legion of Macedonian pikemen.