Cultures and traditions are different in different places, even with gigabit internet and ubiquitous literacy.
Man of those countries speak Germanic languages now since they were invaded by Germanic speaking people after the Western Roman Empire collapsed, but there's still Roman ruins and old Roman cities to be found in all of those countries.
It depends.
We really have no data at all to back such a claim.
We barely even know anything about how metalworkers and other skilled craftsmen organized themselves back in those days in any part of the empire