It's because historically some Gauls migrated with Brennus (not the one who sacked Rome) and settled in Galatia, in modern day central Turkey. That's why Ankyra isn't a Hellenic city, and the Hellenes can only recruit Celts from there. The mercenaries in that area are predominantly Gallic as well. Ankyra can rebel to the Gauls.

I suppose then that the Carthaginians were supposed to have gotten Phoenica from a rebellion, am I correct? If that is what happened, Kudos to the Ptolemaics/Selucids for retaking Phoenica before I noticed.