Of course,

Trade networks are the most likely explanation - people travel independently of goods all the time.

It's interesting that they're turning up on the Hampshire coast - Beaulieu makes for a good, protected landing although what it was like in the neolithic I'm not sure.

Pete

God is our guide! from field, from wave, From plough, from anvil, and from loom; We come, our country's rights to save, And speak a tyrant faction's doom: We raise the watch-word liberty; We will, we will,we will be free!