Hannibal

He had interpreters/translaters from different regions that spoke the multitude of dialects. Plus, most of his men would have picked up some universal battle commands, I would imagine.

Does this clarify for you?

Most of his foreign soldiers fought as bands, under the leadership of captains. It was sufficient that these captains had some notion of Punic for him to be able to deliver his orders.

Besides, he is known as having been a polyglot. In the Punic army, as Polybios tells us when describing the episode of the Truceless War, there were officers especially trained to deal with different nationalities: some with Gauls, some with Numidians and so on. Presumably this included some degree of acquaintance with the language of the soldiers.

So I should think the two layers of the army - Punic leadership and foreign soldiery - meet somewhere in the middle in so far as language was concerned.