Hehehe, you didn't confuse me. Kraut is also an english insult for germans, originating with the prejudice that germans eat a lot of cabbage, just like frogs for french people. So "Fritz" is in fact french for "Kraut" in that regard. As for the other terms, Fridolin is also a first name, but not a very common one. For boches I have no idea.
Btw. I am german, but I never heard about Fritz, but when it was mostly used around WW I and II, that is understandable. And we had / have the german translation of frog eaters as an insult for french in german as well.