More generally, what was Gallic society like at the time? Caesar depicts them as a tribal people, yet they seem to have been able to mobilize armies of tens of thousands of soldiers. So what's the real deal?
There's more to be said (and asked) about it, but you might be interested in these answers to find out why the "tribalism" of late Iron Age Gaul is overstated (and more of a modern re-reading rather than coming from Caesar's account).