Z382 is a broadly Germanic clade in itself since it was formed almost 4000 years ago. Z2040 is even older.
Z382 is found in Scandinavia, North Germany, the Netherlands, England and Lowland Scotland, which makes it both Scandinavian and Anglo-Saxon, which makes sense considering its age. Only deep clades will tell you which is which. As for the labels on the I1 tree, there is only so much that can be written in so little space. The label are just meant to help visualising the broader distribution patterns. For more details, you should check the descriptions in the text below. I changed the name on the tree from Anglo-Saxon to Scandinavian and it became clear that Z382 was also found in Scandinavia - and beyond in places with no Anglo-Saxon connection like Croatia. While Anglo-Saxons can be seen as a branch that split off from Scandinavians, the reverse is not true. Hence I'd keep the 'Anglo-Saxon' appellation for deeper subclades found specifically in Britain.
However if your patrilineal line is from Wallonia, it is almost certainly of Frankish origin, since the Saxon and Vikings only settled in coastal Flanders (around Bruges).