Yes - common roots and archetypes. What I meant was that so few people know anything about the mythologies of Northern Europe and Britain. The Romans pinched and renamed the Greeks gods which in turn came from earlier cultures. They then overlaid their gods on those they came across in the people they conquered and made assumptions. For example the Romans said that the Gauls' chief god was Mercury. Why? We have to try to disentangle that and try to find out who they meant. Cernunnos perhaps? Same thing happened when the Germanic gods were Romanised eg Mars= Tiw, both being gods of war. Our days of the week are named after the sun, moon, Tiw, Woden (Odin), Thor, Frig and Saturn. Wednesday is Mercredi in France (Mercury's day) yet Woden's day in Britain. Not many obvious similarities between Odin and Mercury are there? As the written records were Roman, we have only their distorted accounts to refer to.

Same thing happened with the Germanic pantheon, we have the accounts of Caesar and Tacitus, but Roman versions only. Then when pagan Saxons brought Woden etc to Britain, they soon became Christianised and their religion was lost. The only reason we know as much as we do is because Norse mythology is basically Germanic and was written down in the 13th century Icelandic Eddas by Snorri Sturluson.
Sorry if I've wandered off the point. Get carried away sometimes.