Real Druids are kinda an unknown. We have writings about their practices and beliefs from Roman writers and much later Christian writers. The former were known to be exaggerate and just make shit up when it came to "barbarians" and the enemies of Rome. And the later were often working with incomplete knowledge and also making shit up. This was muddled further by 18th Century work which liked to make ancient cultures even more fantastical. And then you get all the Neo-Pagan revival crap which cast their own beliefs onto ancient cultures, such as the druids, which completely muddied the waters. The fact is, we don't actually know a whole lot about the real Druids.