I think I'd stop at the first source. It's more consistent. We got orange through naranja from Spain. There's no Latin in orange. But in your methodology we got amorous from Latin not French. What's the Ur language behind german?
There is no 'language behind German'. Germanic is just a grouping for any word that derives from one of the related Germanic languages (oftentimes going back to Proto-Germanic). There's certainly another interesting study you could do of the languages of most direct borrowing! But this is in regards to language families or groupings which are significant for English. This would represent something much different, though. Some words, like 'seminar', which have passed through German, would be listed as German, when they're really ultimately Latinate. In my opinion the vibe of the word has much more to do with language family, as any language can be borrowed from regardless of origin.