You are using an incredibly blatant double standard, just compare the way you use the word "romanization" to "germanization":
Apparently romanization merely requires some cultural influence or even just technological infusion but germanization requires annihilation. Why?
Poorly worded myself. I'll aim to correct that.
One of the factors that I feel should be considered to be at play would simply be numbers. The germans who invaded and settled (or were settled) in the Roman Empire originally formed a minority of the local population in those areas. Most of the population of the areas they went into were roman or at least heavily romanized. So to me it feels more likely that being around a more numerous romanized folk led to a movement of romanization rather than one of germanization. That's the main reason I insisted on cultural influence and technological infusion: because it feels more like the colonizers became more like the people they colonized than the other way around.
Doesn't mean of course that there aren't aspects of the original germanic culture that subsisted nor were also adopted by the non-germanic part of the population. But comparatively, I feel you're more encountering a case of romanized barbarians settling in and dominating than of a germanized local population.
The point is that the Franks weren't particularly Romanized in the 5th century CE let alone the 4th one compared to Goths, which adopted Christianity 2-3 generations prior.
We'll have to disagree on that. The Franks, particularly the Salians, had started being settled on the Roman borders by the Romans themselves since the late Third Century, and served as Roman auxiliaries for roughly as much time. This is bound to have had an influence and as far as I'm aware archeology corrolates that.
And again, Christiannity was a relatively new religion that originally didn't correlate to Romanization. In fact, while Christiannity was indeed on the ascent following its legalization and adoption by roman emperors, Paganism wasn't wiped out immediately: it persisted in a lot of areas of the Empire sometimes even after the fall of Rome.
No, I've seen suggested that the nobility remained bilingual up to the 9th century in Neustria.
I don't see how that contradicts the idea that they didn't romanize.
Being bilingual does mean they kept using their germanic language, but it also means they started to adopt the Romance language that was developping... Furthermore, the romance language became the only one being used past the IXth century... Meaning that it was flourishing while the original germanic tongue of the Franks was in decline.
For me it's also a proof of a certain romanization, given they literraly started using their oginal tongue less and less in favor of one heavily influenced by Latin.
Which indicates that they consciously kept a separate identity despite being a minority surrouded by Roman provincials.
Yes but keeping a separate identity doesn't mean you didn't romanize.
In fact, before Caracalla's edict in 212, the Romans themselves used to distinct between proper Roman citizens and non-Romans subjects of the Empire like the Gauls, Britons, Illyrians, Greek, etc... And all the historians I've read on the subject will tell you all these people had romanized to an extent long before Caracalla's edict made everyone a Roman citizen.
So to me the Franks (and other Germanic tribes) making a distinction between themselves and the Romans doesn't really prove much.
Romans don't have a copyright on writing laws.
No... But most of the germanic customs were originally oral traditions and they tended to be given written form only after they settled in former Roman lands.
And even then I don't see how that is contradictory to the idea that adopting Roman law isn't a proof of Romanization. They were after all adopting a whole corpus of laws that weren't their own in the first place. Why bother with that and not stick to only customary laws if you don't think it's relevant and convenient?
This is non-sense, the border regions were the places that show an incredible presence of soldiers from the rest of the empire, which would have made them target of actual linguistic and cultural romanization.
The Roman legion didn't number that much men. In fact, that ended up being one of the downfall of the Roman Empire: the troops were stretched too thin to defend the borders. And while the presence of troops could also have an influence, you could also argue that these are the fringes of the Empire, the more distant parts of it: it would take far more time for them to be properly romanized.
Furthermore, following the Third Century crisis and the troubles of the IVth in the West, Romans were relying more and more on Barbarian
Feodorati to defend themselves. And as a result a lot of those
Feodorati were settled in these border regions. That's actually the main reason you had the Franks settled around the area of modern-day Belgium, because that actually was one of the Northern borders of the Empire.
I'm pretty sure that if you study the border regions of the Western Empire, you'll find that a lot of them had been settled by barbarian tribes tasked with defensive work. Which in turn would mean an inlfux of german settlers in these regions... Regions that were themselves already in contact with germanic tribes for the simple reasons that's what you found on the other side of the border. If not on site should the are not have been properly romanized.
Why does this matter? We weren't talking about the Goths or Italy and Southern France.
Why exclude Northern France from all of this? That's the former part of the Roman Empire that was originally occupied by the Franks... and it definitely spoke a Romance language too.
More importantly it matters because all the germanic tribes, the Franks included, all spoke Germanic language. An argument that about how they would have germanized the land would be the switch in language use to germanic tongues in the areas they occupied: that's one of the points made about the Anglo-Saxon conquest of Britain for example. But in the case of most germanic tribes living in the former western empire, Franks included, the languages that ended up dominating are Romance language all descended from Latin. At best the germanic languages had an influence on how the romance language evolved, but it still remained romance, not a germanic tongue.
There is no reason to believe they did so in any significant capacity before their conquest of Neustria, that's the point.
Most of Neustria is part of what was known as the domain of Soisson that Clovis conquered after he defeated Syagrius.
Childeric I died before that happened and his tomb is in Tournai, a town that is part of Austrasia. And while I don't know much about archelogical finds, I'm pretty sure Childeric's tomb isn't the only one we have in the area that indicates a certain form of romanization.