Per historical records, there were plenty of instances of Rome using hellenic slingers. Most significantly from the Client King of Syracusae, and somewhat in the Illyian Revolts.

Could eb 1.1 have these units recuitable for type 3 and 4 governments in select locations?

I'm really happy to see so much of the AOR change for Romani, most especially in Africa. Still, they cannot recruit anything in certain Carthaginian territories, Sardinia, the Barlaerics, and Carthage most glaringly. Is this historically accurate?