Goidils didn't quite exist yet, but the Erain tribe did (from about the 5th century). At the time they'd just be Q-Celtic speaking Britons though, and would become Goidils sometime around 200 BC. They're something to think about anyway, I know I do, but mostly because I'm very bored, and it matters little if they get in or not to me, so long as I have something to do for the project.