Correct again.
Carthage is currently the biggest faction on the same spot as Seleucids, followed by the Ptolemies. Then, at about the same size, we have the Thracians, Dacians, then the Gallic and Germanic tribes, then the Britons and the Samnites, then Macedon, Pergamon and the Hellenic City States, Iberia etc. The Scythian tribes, although they have a largy map portion, above the Black Sea and having many steppes, they have not so many settlements, being a Nomadic people.
Now, yes, the items aren't culture specific. As for the Persian helmets, they do depend on caps and hoods(kidaris) more than actual helmets. I tried to find reference of actual helmets, not caps, but I haven't come up with anything solid.