Notably the hired units were deployed with their own command structure. As Carthage sent out specific recruiters who bargained contracts with each soldier/corps of soldiers, it is possible that these also served as officers responsible for the integration of their units into the army.
Hired troops were given their own command structures when they joined the army.  Carthage used recruiters to negotiate contracts with individual soldiers and groups of soldiers, which may have also meant those recruiters acted as officers in charge of integrating these new units into the larger army.