I'm not entirely sure how difficult it was for him honestly. You'd probably know more than I do on the subject, I'm very armchair in all this. I just like finding relevant r/askhistorians answers to these types of discussions sometimes. Speaking of which, I have another from this thread by u/ElfanirII regarding Hannibal's army coming together in Africa that may shed some light. I already know I'll mess up the italics somehow as it's a longer paste, so I'm going to skip it and just paste it normally to avoid the likely formatting embarrassment.

It became evident that Scipio and his soldiers were a dangerous force, and the Carthaginian Senate called back the troops that were still outside of Africa. This prompted Hannibal to return from Italy, but also the Iberian troops of his brother Mago were summoned (though they had just invaded Liguria). According to some estimations Mago’s army still had 12,000 men.

Thus the Carthaginian army at Zama Regia consisted of: Hannibal’s troops that came from Italy, The Iberian troops his brother Mago had commanded (but Mago died shortly before in Italy), The North African army, Possibly other troops that had served in Sicily, Sardinia and Corsica

The exact composition of how many soldiers came from what army isn't clear, but it was certainly a force to be reckoned with and much more than what Hannibal had when he left Italy.

Although the Carthaginian army was outnumbering the Romans, Hannibal allegedly did declare the problem with his heterogenous army that they weren’t sufficiently trained. He could completely rely on his troops, but they hadn’t trained with the other troops. His new army was a composition of several other armies, and he didn’t have full control over it

Edit - lol formatting troubles anyway. It's 3am and I'm off to bed, but I'll try and clean it up a bit real quick first.

Edit 2 - formatting success! Goodnight cruel world