>>14938535The Britons were weird because their isolation let them maintain the old ritualistic version of war. Continental Celts adapted to each other and the Romans so they had a more realistic and developed method of battle.
I actually don't know if Briton druids travelled to Europe at the time. I know Gaelic ones went to Stonehenge for teaching but I haven't read much on if communication was common heading back and forth between France and Britain.
