So now we have to write a script for phonological interference across an entire name list, on top of the script for adapting name borrowings. Possible, yes. Cool, yes. But a bitch to do right, and irritating to some (well, at least me) if done wrong.
Also, superstrates generally don't affect phonetics, or really, anything but vocabulary, of the language they assimilate into, unless it's by adding new phonemes. I can't think of any significant Germanic influence on Western Romance phonology, and French had only the smallest effect on English phonology (the biggest one is introducing /v/ as a sound at the beginning of words, and not just as a variant of /f/ after vowels).