I have just noticed that, despite the 189 BCE war between the Roman Republic and the Galatians being referred to in the historical notes, Romans aren't listed in the historical enemies section of the Galatian list. Nor are Galatians listed in the historical enemies section of the Mid-Republican Romans.
I assume an oversight?
Noted in the errata here - https://mortem-et-gloriam.co.uk/smf/index.php?topic=2226.0