It seems to depend somewhat on the name as to which Germanic group was the most likely to have brought it. All of the examples you gave seem Frankish to me as well. A possible counterexample is Bouchard... a Germanic name, and a variant of Burkhart, that does not have a particularly Frankish distribution in France, per here. Bouchard has the -hard suffix and is more likely Burgundian.
Although I bet that if you combined all surnames with that suffix and mapped that, it would look awfully Frankish, at least in France and Belgium.