What Links Are Really Behind These Ancient Migration Claims?

What factors actually link the ancient Israelite tribes to Britain and Germany in the migration theories people discuss today? In Arlo’s Soul Talk # 4: Life So Far, this idea is mentioned, but what historical, cultural, or linguistic evidence do supporters point to? Are these connections based on real archaeological findings or mainly on interpretive biblical narratives? I’m curious how scholars differentiate between myth, symbolism, and documented migration patterns in this debate.