Throughout this site I see the Old German word "wald" being listed as meaning "rule". I can't find any reference to that meaning elsewhere. Today it means "forest" or "woods" in common usage, and in older - though perhaps not Old - usage it seems to have been used to mean hills, upland meadow, and other terms that might fall under the heading not-urban-and-not-farmed.
So I'm wondering if the name WALTER might not be more nearly synonymous with FORREST(ER) than with, say, LORD or KING?
This might not apply to all the names including the "wal-" and "val-" root, as some might have different origins for the same or similar syllable. Given the number of such names listed here, and the number of languages they appear in, that seems likely. However, it seems to me that Old English and other early names of unquestioned Teutonic origin containing that root were probably originally applied as geographic appelations.
On the other hand, given the number of references here to the interpretation with which I'm arguing, I have to assume that there is a counter-argument.