But the root of those germanic words is fulka- and I still don't understand, how are you pre-dating wolk- to uolko- or uolkio- for example. It's a loanword.

As for the distinction, in central europe, there wasn't a germanic ethnicity 'til much later. Take the kinship between the Eluetoi and the western Balts, predating the cimbrian war.
You are juxtaposing germanic nouns in time.